Custom index.php for Subsite

I resolved it with a static page.

Well, I thought I had solved it, but the static page doesn’t give me what I want.

I’m trying to mimic this: https://www.boyscouting.com/Calendar/NewsandEvents.aspx

here: https://gulfridgecouncil.org/newsletter/

I thought I just copy my theme page.php file, rename the copy page-newsletter.php, edit that file to remove the reference to sidebar1.php and then customize the loop to generate the content.
For whatever reason I am missing, that is not working.
Any help is greatly appreciated.

This might be the answer…
https://wordpress.stackexchange.com/a/43172

But not what I really want to do.
Can I add an if statement to the theme index.php page to check if it is the /newsletter subdir, and if so, redirect it to index-newsletter.php?

resolved, if statement worked