onepirsu

This plugin publishes the original NFT. Selling NFTs. 
It is possible to make limited disclosure to users who have NFT.
<h4>Language Translations</h4>
The following language translations are already available:
<ul>
<li>English</li>
<li>Japanese</li>
</ul>

Simple NFT Protection Manager

This plugin publishes the original NFT. Selling NFTs.

hauxh

This plugin allows you to require a secret key that is passed via the URL: http://example.com/post-title/?key=[string] 
Specify the key in a custom value called “key” with the [string] or use the built in widget.
Stable version of the plugin are pushed to the WordPress repository, 
but the latest version of the plugin can be found at: 
https://bitbucket.org/excion/wpkeyme/
Issues/Bugs: https://bitbucket.org/excion/wpkeyme/issues

WPKeyMe

This plugin allows you to require a secret key that is passed via the URL: http://example.com/post-title/?key=[string]

Simple NFT Protection Manager vs WPKeyMe