jpg into web format

You might want to try deleting your Save for Web preferences file.

I haven't got access to a Mac and the directory structure may be different in Big Sur, but you should be looking for something like Users/[Username]/Library/Preferences/Adobe Save For Web 13.0 Prefs and/or 

Users/[Username]/Library/Preferences/Adobe/Plugins/Adobe Save for Web Elements 13

(Unless you bought it through the Apple App Store, in which case there's a more convulated way of getting to them - let us know if that's the case!)

If that doesn't work, assuming you want to keep the image as a JPEG, try using the Save As... feature instead. If you keep JPEG as the file type you'll get a cut-down version of the same settings for JPEGs in the JPEG Options dialog box:

Hopefully, those options will be enough for your needs.

PSE 13 won't work with big sur (well it sorta works, here and there, bits and pieces if it does function at all)--
It's like driving a car where the brakes work sometimes, and soometimes you can start the car, but mostly nope.

you gotta have pse 2021.