If you want to allow you users to post in front-end, you can visit this other article of our documentation: How do I allow users of my site to post articles in front-end?.
Why my users cannot create posts?
To allow your users to create/edit/delete posts with WordPress, they must first have the rights to do so. By default, a user who register to a WP site has a “subscriber” role.
This role is really basic and does not allow such actions to be performed. Your users must therefore have the “author” role, which will allow them to create/modify/delete posts and thus access the form in the front-end.
The simplest way to do this is to change the default role for each newly registered user.
To do this, simply got to Settings > General and use the “New User Default Role” field to select the “author” role.
Note that since the “author” role has the ability to access WordPress dashboard by default, you can use a plugin such as Remove Dashboard Access .
It will allow you to prevent certain roles from accessing your site’s administration screens.
To go further with dashboard restriction, here is an article on How to Limit Dashboard Access in WordPress.
Synchronize WordPress default roles with Paid Memberships Levels
Please make sure you have Paid Memberships Pro and its BuddyPress add-on activated first.
First you have to activate the Roles for Membership Levels add-on of Paid Memberships Pro plugin suite. This plugin will allow you to automatically create a WordPress role for each Memberships Level. Let’s imagine that you have a “PRO” membership level. Each time a user will register with this pricing plan, he will automatically have a WordPress role associated to this memberships level.
After that you can use a plugin like User Role Editor to add or remove custom capabilities via a settings page in the WordPress dashboard for every newly created roles.
For more information about this you can visit the dedicated tutorial form PMPro team here :