Tested the asyncHTTPrequest.h library. The ESP32 crashes on the second request attempt.

asyncHTTPrequest_Test.h

/*
  dependencies:
  https://github.com/me-no-dev/AsyncTCP.git
  https://github.com/tzapu/WiFiManager.git
  https://github.com/boblemaire/asyncHTTPrequest.git
*/

#include <Arduino.h>
#include <WiFi.h>
#include <WiFiManager.h>
#include <asyncHTTPrequest.h>

const char *ssid = "///";
const char *password = "///";

WiFiManager wifiManager;
asyncHTTPrequest request;

void sendRequest()
{
  // here I have intentionally placed a typo to simulate a faulty endpoint
  static bool requestOpenResult = request.open("GET", "http://worldTESTdimeapi.org/api/timezone/Europe/London.txt"); 
  if (request.readyState() == 0 || request.readyState() == 4)
  {
    if (requestOpenResult)
    {
      // Only send() if open() returns true, or crash
      request.send();
      Serial.println("request send");
    }
    else
    {
      Serial.println("Can't send bad request");
    }
  }
  else
  {
    Serial.println("Can't send request");
  }
}

void requestCB(void *optParm, asyncHTTPrequest *request, int readyState)
{
  (void)optParm;

  if (readyState == 4)
  {
    Serial.println(request->responseText());
    Serial.println();
  }
}

void setup()
{
  pinMode(15, INPUT);
  Serial.begin(115200);
  WiFi.setAutoConnect(true);
  WiFi.begin();
  while (WiFi.status() != WL_CONNECTED)
  {
    wifiManager.setConfigPortalTimeout(180);
    Serial.println("Connecting with WiFiManager");
    wifiManager.autoConnect(ssid, password);
    yield();
  }
  request.setDebug(true);
  request.onReadyStateChange(requestCB);
}

void loop()
{
  // when I press the button, it should make a HTTP request
  if (digitalRead(15) == LOW)
  {
    sendRequest();
    delay(500);
  }
}