Yes, bettas can live with kuhli loaches. Kuhli loaches are peaceful bottom-dwellers, so they’ll mostly stay out of the betta’s way. Even though bettas are an aggressive species, they should be able to cohabit with the kuhli loaches without a problem.
With that said, bettas are still very territorial and aggressive, so you need to take extra precautions to avoid any unwanted incidents.
First, make sure the fish have ample space to swim around. Then, provide plenty of decorations and hiding spaces for the kuhli loaches. Last, monitor the tank dynamics regularly, and be prepared to separate them if the bettas start acting hostile.