Louis

This WordPress Plugin add secure headers to you WordPress site.
The Following Headers are included: 
– Strict-Transport-Security: Enforces SSL if your website is using SSL (which it should be) 
– X-Frame-Options: Prevents Clickjacking 
– X-XSS-Protection: Prevents XSS attacks 
– X-Content-Type-Options: set to ‘nosniff to prevent MIME-type sniffing 
– Referrer-Policy: set to ‘no-referrer-when-downgrade’
<ul>
<li>No setup required!</li>
</ul>

WP Secure HTTP Headers

License: GPLv2 or later WordPress plugin to add secure headers to your website.

Dimitar Ivanov

HTTP Headers gives your control over the http headers returned by your blog or website.
Headers supported by HTTP Headers includes:
<ul>
<li>Access-Control-Allow-Origin</li>
<li>Access-Control-Allow-Credentials</li>
<li>Access-Control-Max-Age</li>
<li>Access-Control-Allow-Methods</li>
<li>Access-Control-Allow-Headers</li>
<li>Access-Control-Expose-Headers</li>
<li>Age </li>
<li>Content-Security-Policy</li>
<li>Content-Security-Policy-Report-Only</li>
<li>Cache-Control</li>
<li>Clear-Site-Data</li>
<li>Connection</li>
<li>Content-Encoding</li>
<li>Content-Type</li>
<li>Cross-Origin-Embedder-Policy</li>
<li>Cross-Origin-Opener-Policy</li>
<li>Cross-Origin-Resource-Policy</li>
<li>Expect-CT</li>
<li>Expires</li>
<li>Feature-Policy</li>
<li>NEL</li>
<li>Permissions-Policy</li>
<li>Pragma</li>
<li>P3P</li>
<li>Referrer-Policy</li>
<li>Report-To</li>
<li>Strict-Transport-Security</li>
<li>Timing-Allow-Origin</li>
<li>Vary</li>
<li>WWW-Authenticate</li>
<li>X-Content-Type-Options</li>
<li>X-DNS-Prefetch-Control</li>
<li>X-Download-Options</li>
<li>X-Frame-Options</li>
<li>X-Permitted-Cross-Domain-Policies</li>
<li>X-Powered-By</li>
<li>X-Robots-Tag</li>
<li>X-UA-Compatible</li>
<li>X-XSS-Protection</li>
</ul>

HTTP Headers

Great plugin with a huge amount of settings. Despite the complexity of the setup, the developers have added comments with links to full help. It helps a lot that the comments are also translated into Russian.
After setting up the plugin, be sure to check both the functionality of the site and the speed indicators. Some settings may slow down the site loading speed.

Wonderful

HTTP Headers adds CORS & security HTTP headers to your website.

WP Secure HTTP Headers vs HTTP Headers