Why my christmas cactus does not bloom? What should I do?

Fertilize it and water ones a week. They like moderate sun. Can take full sun I've always had better like with moderate sun. I did hang mine out side under a covered walk way. Who knew the deer loved them. I was able to salvage some repotted. Never to go out sidr again.lol

Your cactus needs the cool Fall nights to bloom. I put mine outside once temps start dipping below 70 here in the south and being it in before the first frost. I have tons of buds within weeks.

https://www.gardeningknowhow.com/ornamental/cacti-succulents/christmas-cactus/how-to-make-a-christmas-cactus-bloom.htm

A very old friend of mine told me recently that after blooming or after the time they should have bloomed you should snap off at least two segments of each branch. That will allow re blooming the next time around. She has them as big as an old wash tub and always snaps them off. I found that fertilizing it about every 3 months helps it for sure. Do NOT give too much water and keep outside in a protected area.

Feed it maybe.......

This is for inside plants. Always works for me.

Care of Christmas Cactus in Bloom. Christmas cactus plants should continue receiving dark, cool treatment for at least 6-8 weeks, or until buds begin forming. Once buds have formed, it usually takes up to 12 weeks (or less) for blooms to appear. The plant should also be relocated at this time.

It's all about the bloom cycle:

https://www.gardeningknowhow.com/ornamental/cacti-succulents/christmas-cactus/how-to-make-a-christmas-cactus-bloom.htm