Post status (tweet) on app's users timeline


Hi, I will make an app and an admin panel, my plan is store user’s token on a db, later in admin panel select a random users and post on their timelines, the problem is idk what endpoints I need to use, I read the docs but not sure what to do.
If someone can help me o point me in the right direction, the app is in php, thanks in advance

Sorry for my bad English