Steps to Get the Link for a Google Maps List

Go to https://www.google.com/maps, to the "Saved" section.

Go to Lists and find the list you want to share.

Click the three-dot menu (⋮) next to the list.

Select "Send link to view"

Click "Get link to share"

Click "Get link"

Click "Copy link"

You can now add this link to Join as a creator.