curl --request POST \
  --url https://api.sandbox.services.payward.com/v1/accounts/{account_id}/on-demand-conversions/estimate \
  --header 'API-Key: <api-key>' \
  --header 'API-Sign: <api-key>' \
  --header 'API-Timestamp: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "from": {
    "symbol": "USD",
    "type": "bank",
    "bank_account": {
      "via": "rfp"
    },
    "amount": "1000.00"
  },
  "to": {
    "symbol": "ETH",
    "type": "wallet",
    "wallet": {
      "via": "ethereum"
    }
  }
}
'

import requests

url = "https://api.sandbox.services.payward.com/v1/accounts/{account_id}/on-demand-conversions/estimate"

payload = {
    "from": {
        "symbol": "USD",
        "type": "bank",
        "bank_account": { "via": "rfp" },
        "amount": "1000.00"
    },
    "to": {
        "symbol": "ETH",
        "type": "wallet",
        "wallet": { "via": "ethereum" }
    }
}
headers = {
    "API-Key": "<api-key>",
    "API-Sign": "<api-key>",
    "API-Timestamp": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'API-Key': '<api-key>',
    'API-Sign': '<api-key>',
    'API-Timestamp': '<api-key>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    from: {symbol: 'USD', type: 'bank', bank_account: {via: 'rfp'}, amount: '1000.00'},
    to: {symbol: 'ETH', type: 'wallet', wallet: {via: 'ethereum'}}
  })
};

fetch('https://api.sandbox.services.payward.com/v1/accounts/{account_id}/on-demand-conversions/estimate', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.sandbox.services.payward.com/v1/accounts/{account_id}/on-demand-conversions/estimate",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'from' => [
        'symbol' => 'USD',
        'type' => 'bank',
        'bank_account' => [
                'via' => 'rfp'
        ],
        'amount' => '1000.00'
    ],
    'to' => [
        'symbol' => 'ETH',
        'type' => 'wallet',
        'wallet' => [
                'via' => 'ethereum'
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "API-Key: <api-key>",
    "API-Sign: <api-key>",
    "API-Timestamp: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.sandbox.services.payward.com/v1/accounts/{account_id}/on-demand-conversions/estimate"

	payload := strings.NewReader("{\n  \"from\": {\n    \"symbol\": \"USD\",\n    \"type\": \"bank\",\n    \"bank_account\": {\n      \"via\": \"rfp\"\n    },\n    \"amount\": \"1000.00\"\n  },\n  \"to\": {\n    \"symbol\": \"ETH\",\n    \"type\": \"wallet\",\n    \"wallet\": {\n      \"via\": \"ethereum\"\n    }\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("API-Key", "<api-key>")
	req.Header.Add("API-Sign", "<api-key>")
	req.Header.Add("API-Timestamp", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.sandbox.services.payward.com/v1/accounts/{account_id}/on-demand-conversions/estimate")
  .header("API-Key", "<api-key>")
  .header("API-Sign", "<api-key>")
  .header("API-Timestamp", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"from\": {\n    \"symbol\": \"USD\",\n    \"type\": \"bank\",\n    \"bank_account\": {\n      \"via\": \"rfp\"\n    },\n    \"amount\": \"1000.00\"\n  },\n  \"to\": {\n    \"symbol\": \"ETH\",\n    \"type\": \"wallet\",\n    \"wallet\": {\n      \"via\": \"ethereum\"\n    }\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.sandbox.services.payward.com/v1/accounts/{account_id}/on-demand-conversions/estimate")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["API-Key"] = '<api-key>'
request["API-Sign"] = '<api-key>'
request["API-Timestamp"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"from\": {\n    \"symbol\": \"USD\",\n    \"type\": \"bank\",\n    \"bank_account\": {\n      \"via\": \"rfp\"\n    },\n    \"amount\": \"1000.00\"\n  },\n  \"to\": {\n    \"symbol\": \"ETH\",\n    \"type\": \"wallet\",\n    \"wallet\": {\n      \"via\": \"ethereum\"\n    }\n  }\n}"

response = http.request(request)
puts response.read_body

{
  "data": {
    "from": {
      "symbol": "USD",
      "type": "bank",
      "amount": "1000.00"
    },
    "to": {
      "symbol": "ETH",
      "type": "wallet",
      "amount": "0.39770000"
    },
    "rate": {
      "base": {
        "symbol": "USD"
      },
      "quote": {
        "symbol": "ETH"
      },
      "price": "0.0004"
    },
    "fees": {
      "from": {
        "symbol": "USD",
        "amount": "0.00"
      },
      "trade": {
        "symbol": "USD",
        "amount": "5.00"
      },
      "to": {
        "symbol": "ETH",
        "amount": "0.00030000"
      }
    }
  }
}

{
  "error": {
    "type": "conversions_error",
    "instance": "5f4d2a8e-91a4-4d6c-8a17-9b1e2c3f4a5b",
    "status": 400,
    "code": "bad_request",
    "causes": [
      {
        "field": "account_id",
        "message": "must be a valid account identifier"
      }
    ]
  }
}

{
  "error": {
    "type": "conversions_error",
    "instance": "5f4d2a8e-91a4-4d6c-8a17-9b1e2c3f4a5b",
    "status": 401,
    "code": "unauthenticated"
  }
}

{
  "error": {
    "type": "conversions_error",
    "instance": "5f4d2a8e-91a4-4d6c-8a17-9b1e2c3f4a5b",
    "status": 403,
    "code": "forbidden"
  }
}

{
  "error": {
    "type": "conversions_error",
    "instance": "5f4d2a8e-91a4-4d6c-8a17-9b1e2c3f4a5b",
    "status": 429,
    "code": "resource_exhausted"
  }
}

{
  "error": {
    "type": "conversions_error",
    "instance": "5f4d2a8e-91a4-4d6c-8a17-9b1e2c3f4a5b",
    "status": 500,
    "code": "internal"
  }
}

{
  "error": {
    "type": "conversions_error",
    "instance": "5f4d2a8e-91a4-4d6c-8a17-9b1e2c3f4a5b",
    "status": 503,
    "code": "unavailable"
  }
}

{
  "error": {
    "type": "conversions_error",
    "instance": "5f4d2a8e-91a4-4d6c-8a17-9b1e2c3f4a5b",
    "status": 504,
    "code": "deadline_exceeded"
  }
}