Install-Package Owl.reCAPTCHA 

services.AddreCAPTCHAV3(x => { x.SiteKey = "your_site_key"; x.SiteSecret = "your_site_secret"; }); 

@addTagHelper *, Owl.reCAPTCHA <form method="POST"> <input id="token" name="token" type="text" /> <input id="submit" type="submit" value="submit" /> </form> <recaptcha-script-v3 /> @* Hide-the-recaptcha-badge https://developers.google.com/recaptcha/docs/faq#id-like-to-hide-the-recaptcha-badge.-what-is-allowed <recaptcha-script-v3 hide-badge="true" /> *@ <script> function callback(token) { document.getElementById("token").value = token; } </script> <recaptcha-script-v3-js action="login" callback="callback" /> 

@addTagHelper *, Owl.reCAPTCHA <form method="POST" id="recaptchaForm"> <input id="token" name="token" type="text" /> <input id="submitBtn" type="submit" value="submit" /> </form> <script> document.getElementById("submitBtn").onclick = function(e) { e.preventDefault(); grecaptcha.reExecute(function(token) { document.getElementById("token").value = token; document.getElementById("recaptchaForm").submit(); }) }; </script> <recaptcha-script-v3 /> @* Hide-the-recaptcha-badge https://developers.google.com/recaptcha/docs/faq#id-like-to-hide-the-recaptcha-badge.-what-is-allowed <recaptcha-script-v3 hide-badge="true" /> *@ <recaptcha-script-v3-js action="login" execute="false" /> 

public class V3Model : PageModel {	private readonly IreCAPTCHASiteVerifyV3 _siteVerify;	public V3Model(IreCAPTCHASiteVerifyV3 siteVerify)	{	_siteVerify = siteVerify;	}	public async Task OnPostAsync(string token)	{	var response = await _siteVerify.Verify(new reCAPTCHASiteVerifyRequest	{	Response = token,	RemoteIp = HttpContext.Connection.RemoteIpAddress.ToString()	}); /* https://developers.google.com/recaptcha/docs/v3 response: { "success": true|false, // whether this request was a valid reCAPTCHA token for your site "score": number // the score for this request (0.0 - 1.0) "action": string // the action name for this request (important to verify) "challenge_ts": timestamp, // timestamp of the challenge load (ISO format yyyy-MM-dd'T'HH:mm:ssZZ) "hostname": string, // the hostname of the site where the reCAPTCHA was solved "error-codes": [...] // optional } */	} } 

services.AddreCAPTCHAV2(x => { x.SiteKey = "your_site_key"; x.SiteSecret = "your_site_secret"; }); 

@addTagHelper *, Owl.reCAPTCHA <recaptcha-script-v2 /> <script> function callback(token) { document.getElementById("token").value = token; } </script> <form method="POST"> <input id="token" name="token" type="text" /> <input id="submit" type="submit" value="submit" /> </form> <recaptcha-div-v2 callback="callback" /> 

@addTagHelper *, Owl.reCAPTCHA <script> function onload() { grecaptcha.execute(); } function callback(token) { document.getElementById("token").value = token; } </script> <recaptcha-script-v2 onload="onload" /> @* Hide-the-recaptcha-badge https://developers.google.com/recaptcha/docs/faq#id-like-to-hide-the-recaptcha-badge.-what-is-allowed <recaptcha-script-v2 hide-badge="true" /> *@ <form method="POST"> <input id="token" name="token" type="text" /> <input id="submit" type="submit" value="submit" /> </form> <recaptcha-div-v2 callback="callback" size="invisible" /> 

@addTagHelper *, Owl.reCAPTCHA <script> function callback(token) { document.getElementById("token").value = token; document.getElementById("demo-form").submit(); } </script> <recaptcha-script-v2 /> @* Hide-the-recaptcha-badge https://developers.google.com/recaptcha/docs/faq#id-like-to-hide-the-recaptcha-badge.-what-is-allowed <recaptcha-script-v2 hide-badge="true" /> *@ <form id="demo-form" method="POST"> <input id="token" name="token" type="text" /> <button recaptcha-v2-callback="callback" recaptcha-v2-size="invisible">Submit</button> </form> 

public class V2_CheckboxModel : PageModel {	private readonly IreCAPTCHASiteVerifyV2 _siteVerify;	public V2_CheckboxModel(IreCAPTCHASiteVerifyV2 siteVerify)	{	_siteVerify = siteVerify;	}	public async Task OnPostAsync(string token)	{	var response = await _siteVerify.Verify(new reCAPTCHASiteVerifyRequest	{	Response = token,	RemoteIp = HttpContext.Connection.RemoteIpAddress.ToString()	}); /* https://developers.google.com/recaptcha/docs/verify response: { "success": true|false, "challenge_ts": timestamp, // timestamp of the challenge load (ISO format yyyy-MM-dd'T'HH:mm:ssZZ) "hostname": string, // the hostname of the site where the reCAPTCHA was solved "error-codes": [...] // optional } */	} }