How to get PageID of a Facebook user for which user is admin and get permissions to post on it in ASP.NET MVC?

You can get user pages using Graph API. Steps:

1. Get the manage_pages permission from the user (extended permissions).
2. Call the Graph API - https://graph.facebook.com/me/accounts

You can test this procedure in the graph explorer -> Just click on 'Get Access Token' button-> under 'Extended permission' check 'manage_pages' & submit it. It will give you the admin-page-details JSON.

Source

Some more links which may help

https://stackoverflow.com/questions/13856918/facebook-c-sharp-sdk-how-to-get-all-user-facebook-pages

https://gwu-libraries.github.io/sfm-ui/posts/2018-01-02-facebook

https://docs.oneall.com/api/resources/providers/facebook/list-all-pages/

The above links should help you if you have knowledge of Graph API, if not you can read this article which may help.

Thanks so much Vinnu your answar help me alot of :) .