Q.how to get bougainvillea to bloom,
I live in south FL; they get full sun, I feed them every 2 weeks VPG 17-7-10.
I prune them, so they are fully developed.
Certified GKH Gardening Expert
Unfortunately, these plants will need the exact opposite care!
They won't want to be fed very often, and when you do feed them you will need to stay away from high nitrogen foods.
They are a bit sensitive to water, also. You will want to hold off on watering, usually, unless they absolutely need it!
Pruning needs to be kept to a minimum, or not at all. This is another common reason for not flowering with this species.
This article will give you more information: https://www.gardeningknowhow.com/ornamental/vines/bougainvillea/bougainvillea-not-blooming.htm