When I was in middle school, we used to pick up free magnets from businesses that would give them out as promotional material, or even, phone books would come with free magnets. Then we'd print off pictures of anime characters and glue them on the magnets so we could stick 'em on the inside of our lockers. The magnets were thin enough that you could cut them into whatever size/shape you wanted.
In retrospect, it looked super trashy done like that. But I'd imagine you could get one of those
nice phone straps and glue a magnet on the back of it.
Shrink film is also something you can use to print whatever you want off in a way that's quite a bit more classy than just regular printer paper.
Magnets are also something that pop up quite often on Etsy, because they're quite easy to make, and an easy way for an artist to market their drawing talent. So if you don't want to do any work and you're into the idea of supporting
cool fanart, that's an option too.
I know it's not the official stuff y'all are hoping for, but I'm a seasoned veteran in not getting the merch I want for things. Ya learn tricks.