Are there any precautions for neck wrinkle fillers?

Perhaps because I often read books while lying down, I am very concerned about the deep horizontal wrinkles on my neck and the fat deposits under my chin, which make my lower facial line look dull. I have become interested in neck wrinkle fillers to smoothly fill in these deep lines and have planned a visit to a dermatologist. While researching contouring before the procedure, I learned that combining them with Belkyra injections, which destroy unnecessary fat cells under the chin, significantly enhances the neckline. I am wondering how often Belkyra treatments should typically be administered to ensure safety. Please provide guidance on the synergy that occurs in line refinement when fillers and Belkyra are combined at appropriate intervals. Thank you.