(Question) Is there a way to reduce Botox resistance?

My mother was very worried that her deep frown lines made her look fierce, so she received Botox injections for the forehead area. She plans to get Botox regularly in the future, but I heard that resistance develops easily, which reduces its effectiveness. In that case, I am wondering if there is a specific way to prevent resistance from developing, or if there is a particular method for managing it.