❔ How to access a button from a different class?

Hello. Recently, I was developing a project and decided to start splitting my code into separate files instead of keeping everything in form1.cs. I'm a beginner, and this may be a very basic question, but I really don't know how to access a button or another designer element from a different class other than form1.cs. I've searched everywhere, but I couldn't find a tutorial that taught me this.