How about Content Security Policy in This Package about laravel-recaptcha HOT 1 CLOSED

You would likely have to modify the ReCaptchaBuilderV3.php or other version you are using to add such a header.
Maybe it could be passed through the $configuration object or detect if csp_nonce function is existing?

$nonce= $configuration['cspCode'] ?? null;
if (function_exists('csp_nonce')) {
  $nonce= csp_nonce();
}

$html = "<script src=\"" . $this->api_js_url . "?render={$this->api_site_key}\" ".($nonce!== null ? "nonce=\"".$nonce."\"" : '') ."></script>";

Alternatively the function just returns a string to put in blade template or some other output right, you could wrap it and replace to add it in.

Was reading more on it here.
Maybe need to do it on other script tag as well not sure.
https://www.vicarius.io/blog/prevent-attacks-using-nonce-attribute

from laravel-recaptcha.