One header, one endpoint, one JSON body.

import os, requests

response = requests.get(
    "https://tickatlas.com/v1/indicator",
    headers={"X-API-Key": os.environ["TICKATLAS_API_KEY"]},
    params={"symbol": "EURUSD", "indicator": "RSI_14", "timeframe": "H1"},
    timeout=10,
)
response.raise_for_status()

data = response.json()["data"]
print(f"{data['indicator']} = {data['value']} at {data['server_time']}")

const url = new URL("https://tickatlas.com/v1/indicator");
url.search = new URLSearchParams({
  symbol: "EURUSD",
  indicator: "RSI_14",
  timeframe: "H1",
});

const res = await fetch(url, {
  headers: { "X-API-Key": process.env.TICKATLAS_API_KEY },
});
if (!res.ok) throw new Error((await res.json()).error.code);

const { data } = await res.json();
console.log(`${data.indicator} = ${data.value} at ${data.server_time}`);

<?php
$query = http_build_query([
    'symbol'    => 'EURUSD',
    'indicator' => 'RSI_14',
    'timeframe' => 'H1',
]);

$ch = curl_init("https://tickatlas.com/v1/indicator?$query");
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER     => ['X-API-Key: ' . getenv('TICKATLAS_API_KEY')],
]);

$body = json_decode(curl_exec($ch), true);
curl_close($ch);

printf("%s = %s at %s\n",
    $body['data']['indicator'], $body['data']['value'], $body['data']['server_time']);

package main

import (
    "encoding/json"
    "fmt"
    "net/http"
    "os"
)

type indicatorResponse struct {
    Success bool `json:"success"`
    Data    struct {
        Indicator  string  `json:"indicator"`
        Value      float64 `json:"value"`
        ServerTime string  `json:"server_time"`
    } `json:"data"`
}

func main() {
    req, _ := http.NewRequest("GET",
        "https://tickatlas.com/v1/indicator?symbol=EURUSD&indicator=RSI_14&timeframe=H1", nil)
    req.Header.Set("X-API-Key", os.Getenv("TICKATLAS_API_KEY"))

    res, err := http.DefaultClient.Do(req)
    if err != nil {
        panic(err)
    }
    defer res.Body.Close()

    var out indicatorResponse
    json.NewDecoder(res.Body).Decode(&out)
    fmt.Printf("%s = %.2f at %s\n", out.Data.Indicator, out.Data.Value, out.Data.ServerTime)
}