user defined function

Hi and welcome to the forum,

First of all - please edit the title of your post to be more spoecific - you are asking not just about UDF, but how to add help file to it. see rule 1 of: https://www.excelforum.com/forum-rul...rum-rules.html

As you are using version 2020 of excel, the method described in https://stackoverflow.com/questions/...ined-functions shall work for you.