I’ve never used clicker training before, but I did have some of my bunnies trained to come to me when I made a specific sound with my mouth.
My guess is you should start out on moments she is outside, but near her cage. make sure she’s always a bit hungry during training moments, so she’ll definitly have interest in treats. trainingsessions should be short and very often repeated so better 5times a day for 5 minutes than 1time a
In the beginning, get her attention first, let her know you are holding treats, pet her a litlle, get to sit right next to the cage.
than make a specific sound (clicker, or the word ‘cage’ or something like that) at the same time put your hand with the treat in the cage and give her one. make sure she actually gets in the cage before you give the treat. repeat untill she immediatly follows your hand that goes in the cage.
now try to sit a litlle bit further from the cage, but make sure you can still reach it, do the same. If she really gets it and always follows your hand. start dropping the treat on the floor of her cage before she can take it from your hand.
try moving further and further away untill you have to throw the treat a litlle bit
most importantly: always make the sound and give her a treat when she casualy walks in her cage.
be patient and before too long she’ll see the link