bepayper

This plugin adds Payper capabilities in WordPress. 
It works for standard or custom posts, and it can be configured for any type of theme.

Payper widget

Allows to add Payper widget in a Wordpress site.

leadhospitality

Content Revenue Engine is a monetization plugin for WordPress designed for publishers, premium blogs, media sites, membership-driven content businesses, and knowledge brands that want more than a basic paywall.
With CRE Free you can combine: 
* Metered paywall rules 
* Pay Per Post monetization 
* Stripe payments 
* Conversion-focused CTA and notices 
* Paywall exemptions and content rules 
* Dashboard, Inspector, and Sales
CRE Free includes one Pay Per Post category and one default PPP price, with a direct upgrade path to PRO for advanced paid categories, tags, post-level pricing, and broader monetization controls.

Content Revenue Engine

Paywall and Pay Per Post for WordPress. Monetize premium content and control access with Stripe.

Payper widget vs Content Revenue Engine