Custom capabilities

This post may give you the answer
https://shinephp.com/capabilities-set-for-custom-post-type/

That gives instructions that involve making a new custom post type within the plugin. But how should I do it if the custom post type already exists?

Please read more carefully.
According to that post you need to check at the plugin code how it defines custom post type, e.g. ‘card’ or something else and what capability it uses for it. Sometimes plugin creates own custom post type, but uses default ‘post’ capability to manage access to it.

After that you may add the set of custom user capabilities for that custom post type, as described at the end of the post I noted above, on the example of ‘card’ custom post type – 10 custom capabilities.

Thank you I checked after my last reply and I will try that with the plugin. Thanks