How to add

https://myfitnesspal.desk.com/customer/en/portal/articles/12032-how-do-i-invite-a-current-member-to-be-my-friend-on-myfitnesspal-

https://myfitnesspal.desk.com/customer/en/portal/articles/306079-how-do-i-invite-a-friend-to-join-myfitnesspal-

Not sure which of the above will help.

Click their name, then click their name again when the box comes up, then click "Add as a friend."

After you do that, the member will get a message asking to add you as their friend. They can accept or reject that request. If they accept, they'll turn up in your Friend List on your profile page.