You might want to download 30 day full function free trials of Helicon Focus and Zerene Stacker. These are both very good (I have both but prefer Helicon Focus, but a lot of people, perhaps the majority, prefer Zerene Stacker). However, they are quite expensive.
CombineZP is free. It is less sophisticated than Zerene or Helicon but fine for some people's purposes.
Some photo editors do stacking. Affinity Photo is one, and that is I think much less expensive than Zerene or Helicon. I don't know how good its stacking is. I understand there is a 10 day full function free trial of Affinity Photo.