If you don’t see the Add Friend button on someone’s profile, it may be because they have disabled Friend Requests in their privacy settings.
Some users choose not to receive friend requests, and in that case, the option to add them will not appear.
To check or manage your own Friend Request settings:
Open the Insight Timer app.
Tap the menu icon (☰) in the top-left corner.
Tap Settings.
Select Account & Privacy.
Tap Friend Requests.
Toggle the feature on or off.
When enabled, other users will be able to send you friend requests.