In order to edit the "Sign-up" popup, please go to Dashboard > Templates > Popups

Locate the "Sign Up Popup" and click on Edit with Elementor:

Please check these guides for further information:

Guide to Vamtam Elementor Builder

Popup Elementor

Next, click on the "Save options" icon and select "Display conditions":

Here, you can remove the popup from the homepage or add it to whichever post or page:

Please check this tutorial for more details: Display conditions Elementor