Q.Fish bone cactus how to make it flower?
Fish bone cactus grows easy, outdoor in ground, clay soil, full sun, but never flowers for me. I suspect it may be the cold and rain during Melbourne winter.
These plants require warmth with high humidity. They should be kept at 16–25°C (61–77°F), it may drop to 10–15°C (50–59°F) for shorter periods. Mist spray them daily and stand the pots on trays or saucers of moist pebbles.
After flower buds start to form, apply a tomato-type fertilizer every two weeks. Stop feeding when most buds are open.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/fishbone-cactus/orchid-cactus-care.htm