This is a really old exploit that originates all the way back to 2017/2018. 
Essentially, it prevents your tab from being closed in the most simple way. Use as needed.

Instructions: 
1. Create a bookmark.
2. Copy one of the provided bookmarklets (code) below.
3. Paste it in as the URL.
4. Name it whatever you want and click Save.
5. Run on whatever tab you want to prevent from being force closed!

1:
javascript: onbeforeunload = (i) => 1;

2:
javascript:onbeforeunload=i=>1

Credits:
https://github.com/titaniumnetwork-dev/Oxide-Docs/blob/master/docs/kajigs.mdx
Titanium Network
theskid22
Arsun
