Positiong FF on the screen? (Linux)

[P38Usul]

Is there a way to open FF on only part of the screen, in the same place all the time?

I would like it to be full height and touch on the right side but not on the left. That allows Thunderbird to peek through and I can see if I have mail.
I used to be able to put the screen where I wanted it and when I restarted it would be in the same place, but something changed.
Now if I stretch FF over to the right side it suddenly goes to full-screen, so I have to hold it back just a bit.
It would be nice if there were a setting somewhere that would allow you to map out exactly where to open it.

Firefox 107.0 Kubuntu 22.04

Thanks

[morat]

Maybe an addon would help?

Simple Window Resizer by Soustruh
http://addons.mozilla.org/firefox/addon/735895

Change New Maximized Window to Resizable by jscher2000
http://addons.mozilla.org/firefox/addon/2614151

Chrome has --window-size and --window-position command line options.

Firefox has --window-size command line option, but not --window-position.

[P38Usul]

Simple Window Resizer by Soustruh works just as I hoped.
Thank you