Contact forms stopped working

Contact forms on our website www.allegrakrstarenja.com stopped working... Wheel keeps spinning...

I commented following lines in sendemail.php, so we don-t force recaptcha

		// if( !isset( $_POST['g-recaptcha-response'] ) ) {
		// 	echo '{ "alert": "error", "message": "Greška u Captcha verifikaciji! Molimo pokušajte ponovo." }';
		// 	die;
		// }

And this is alert I get from recaptcha admin:
We detected that your site is not verifying reCAPTCHA solutions. This is required for the proper use of reCAPTCHA on your site. Please see our developer site for more information.

Canvas version is 4.5.1

We currently can't migrate to newer version cause of time and resource limit

Update:

Forms on url https://www.allegrakrstarenja.com/kontakt.html now is working, without recaptcha div...

Dear, we checked with hosting provider, and they said that allow_url_fopen is enabled all the time

We need to be clear, these forms worked, but suddenly stopped working, should we try different recaptcha codes or something else?
Please advise

This is block of code that is not passing

			// Runs only when reCaptcha is present in the Contact Form
			if( isset( $_POST['g-recaptcha-response'] ) ) {
				$recaptcha_response = $_POST['g-recaptcha-response'];
				$response = file_get_contents( "https://www.google.com/recaptcha/api/siteverify?secret=" . $recaptcha_secret . "&response=" . $recaptcha_response );

				$g_response = json_decode( $response );

				if ( $g_response->success !== true ) {
					echo '{ "alert": "error", "message": "Greška u ReCaptcha verifikaciji! Molimo pokušajte ponovo." }';
					die;
				}
			}

We tried new set of keys, but no success

Please advise

Hello all,
this is code that I used for implementing Recaptcha, hope that will helps someone else struggling with this same issue.

			// Runs only when reCaptcha is present in the Contact Form
			if( isset( $_POST['g-recaptcha-response'] ) ) {
				$recaptcha_response = $_POST['g-recaptcha-response'];
				
				$data = array(
					'secret' => $recaptcha_secret,
        			'response' => $recaptcha_response
				);

				$verify = curl_init();
				curl_setopt($verify, CURLOPT_URL, "https://www.google.com/recaptcha/api/siteverify");
				curl_setopt($verify, CURLOPT_POST, true);
				curl_setopt($verify, CURLOPT_POSTFIELDS, http_build_query($data));
				curl_setopt($verify, CURLOPT_SSL_VERIFYPEER, false);
				curl_setopt($verify, CURLOPT_RETURNTRANSFER, true);
				$response = curl_exec($verify);
				curl_close($verify);
				
				$json = json_decode($response, true);
        		if($json["success"] !== true) { 
					echo '{ "alert": "error", "message": "Captcha not Validated! Please Try Again." }';
					die;
				}

			}

			// Uncomment the following Lines of Code if you want to Force reCaptcha Validation

			 if( !isset( $_POST['g-recaptcha-response'] ) ) {
			 	echo '{ "alert": "error", "message": "Captcha not Submitted! Please Try Again." }';
			 	die;
			}

It worked with file_get_contents but stopped due to ReCaptcha update and verifying over https

curl_setopt($verify, CURLOPT_SSL_VERIFYPEER, false);