How do I add users to account on TV?

Apple ID accounts are individual and should not be shared. These accounts do not feature “user profiles” like some streaming providers have. [Apple ID accounts are used much more broadly than just streaming access.]

You can share select services, including Apple TV+, in a Family Sharing setting. By defining a group, each member can access this service on their own Apple ID account. The ‘organizer’ must have an iPhone, iPad, iPod Touch, or Mac to set it up.

Family Sharing - Apple

What you can do with Family Sharing - Apple Support

Set up Family Sharing - Apple Support

For keeping watch lists (etc.) separate on a single Apple TV box (4th generation or later), you may add multiple users, each by their own Apple ID account. Then switch to the intended user before watching through that account.

Set up multiple users on Apple TV - Apple Support

For keeping watch lists (etc.) separate on a single third party device with the Apple TV app, you may add multiple users, each by their own Apple ID account. Then switch to the intended user before watching through that account.

Add additional Apple ID accounts - Family Sharing in the Apple TV app - Apple Support