curl --request POST \
  --url https://rpc.etherspot.io/v1/137/ \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "method": "eth_estimateUserOperationGas",
  "params": [
    {
      "sender": "<string>",
      "nonce": "<string>",
      "initCode": "<string>",
      "callData": "<string>",
      "paymasterAndData": "<string>",
      "callGasLimit": "<string>",
      "verificationGasLimit": "<string>",
      "preVerificationGas": "<string>",
      "maxPriorityFeePerGas": "<string>",
      "maxFeePerGas": "<string>",
      "signature": "<string>"
    }
  ],
  "id": 123
}
'

import requests

url = "https://rpc.etherspot.io/v1/137/"

payload = {
    "jsonrpc": "2.0",
    "method": "eth_estimateUserOperationGas",
    "params": [
        {
            "sender": "<string>",
            "nonce": "<string>",
            "initCode": "<string>",
            "callData": "<string>",
            "paymasterAndData": "<string>",
            "callGasLimit": "<string>",
            "verificationGasLimit": "<string>",
            "preVerificationGas": "<string>",
            "maxPriorityFeePerGas": "<string>",
            "maxFeePerGas": "<string>",
            "signature": "<string>"
        }
    ],
    "id": 123
}
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    jsonrpc: '2.0',
    method: 'eth_estimateUserOperationGas',
    params: [
      {
        sender: '<string>',
        nonce: '<string>',
        initCode: '<string>',
        callData: '<string>',
        paymasterAndData: '<string>',
        callGasLimit: '<string>',
        verificationGasLimit: '<string>',
        preVerificationGas: '<string>',
        maxPriorityFeePerGas: '<string>',
        maxFeePerGas: '<string>',
        signature: '<string>'
      }
    ],
    id: 123
  })
};

fetch('https://rpc.etherspot.io/v1/137/', 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://rpc.etherspot.io/v1/137/",
  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([
    'jsonrpc' => '2.0',
    'method' => 'eth_estimateUserOperationGas',
    'params' => [
        [
                'sender' => '<string>',
                'nonce' => '<string>',
                'initCode' => '<string>',
                'callData' => '<string>',
                'paymasterAndData' => '<string>',
                'callGasLimit' => '<string>',
                'verificationGasLimit' => '<string>',
                'preVerificationGas' => '<string>',
                'maxPriorityFeePerGas' => '<string>',
                'maxFeePerGas' => '<string>',
                'signature' => '<string>'
        ]
    ],
    'id' => 123
  ]),
  CURLOPT_HTTPHEADER => [
    "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://rpc.etherspot.io/v1/137/"

	payload := strings.NewReader("{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"eth_estimateUserOperationGas\",\n  \"params\": [\n    {\n      \"sender\": \"<string>\",\n      \"nonce\": \"<string>\",\n      \"initCode\": \"<string>\",\n      \"callData\": \"<string>\",\n      \"paymasterAndData\": \"<string>\",\n      \"callGasLimit\": \"<string>\",\n      \"verificationGasLimit\": \"<string>\",\n      \"preVerificationGas\": \"<string>\",\n      \"maxPriorityFeePerGas\": \"<string>\",\n      \"maxFeePerGas\": \"<string>\",\n      \"signature\": \"<string>\"\n    }\n  ],\n  \"id\": 123\n}")

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

	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://rpc.etherspot.io/v1/137/")
  .header("Content-Type", "application/json")
  .body("{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"eth_estimateUserOperationGas\",\n  \"params\": [\n    {\n      \"sender\": \"<string>\",\n      \"nonce\": \"<string>\",\n      \"initCode\": \"<string>\",\n      \"callData\": \"<string>\",\n      \"paymasterAndData\": \"<string>\",\n      \"callGasLimit\": \"<string>\",\n      \"verificationGasLimit\": \"<string>\",\n      \"preVerificationGas\": \"<string>\",\n      \"maxPriorityFeePerGas\": \"<string>\",\n      \"maxFeePerGas\": \"<string>\",\n      \"signature\": \"<string>\"\n    }\n  ],\n  \"id\": 123\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://rpc.etherspot.io/v1/137/")

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

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"jsonrpc\": \"2.0\",\n  \"method\": \"eth_estimateUserOperationGas\",\n  \"params\": [\n    {\n      \"sender\": \"<string>\",\n      \"nonce\": \"<string>\",\n      \"initCode\": \"<string>\",\n      \"callData\": \"<string>\",\n      \"paymasterAndData\": \"<string>\",\n      \"callGasLimit\": \"<string>\",\n      \"verificationGasLimit\": \"<string>\",\n      \"preVerificationGas\": \"<string>\",\n      \"maxPriorityFeePerGas\": \"<string>\",\n      \"maxFeePerGas\": \"<string>\",\n      \"signature\": \"<string>\"\n    }\n  ],\n  \"id\": 123\n}"

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