How can I add Steam friends on Apex for gifting?

I just started playing Apex Legends a month ago. I am playing with my friends through Steam, and they are on my friends list. Now, there is an event for people to gift for a skin. I cannot be sent gifts nor send gifts to my friends. I read that we should be in game friends, but there is no option for me to send friend request because we are already friends through Steam. How can I add them and gift them for the event? Thanks!