If you are not receiving friend's invite please check that your Friend Invite Permission is not set to 'noone' under the Social Privacy.
- Sign-in in Fortnite.
- Click main menu on top left corner
- Click the Cog Setting
on the bottom left bar
- Click Settings
- Click Account and Privacy
- Under Social Privacy, review your Friend Invite Permission to chose who can send you a friend invite: Anyone, friends of friends or noone.
- After choosing your preference, click apply.