example-recaptcha.html

<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8" />
		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
		<title>Recaptcha v3 token testing</title>
		<script src="https://www.google.com/recaptcha/api.js?render=your-recaptcha-code-from-admin-panel"></script>
	</head>
	<body>
		<h1 id="recaptchaResponse"></h1>
		<button id="copy">copy</button>
	</body>
	<script>
		grecaptcha.ready(function () {
			grecaptcha
				.execute("your-recaptcha-code-from-admin-panel", {
					//replace this content with your PRIVATE api key. Here and in 7th line code
					action: "contact",
				})
				.then((response) => {
					console.log(response);
					document.getElementById("recaptchaResponse").innerText =
						response;
				});
		});

		document.querySelector("#copy").addEventListener("click", function () {
			var tempElem = document.createElement("textarea");
			tempElem.value =
				document.getElementById("recaptchaResponse").textContent;
			document.body.appendChild(tempElem);

			tempElem.select();
			document.execCommand("copy");
			document.body.removeChild(tempElem);
		});
	</script>
</html>