Photos taken for portrait sitting with green screen

[SufferWell]

I had a stand alone program with replacement backgrounds however, It is gone. How can I replace a background on a green screen photograph? I have been searching for a tutorial etc. Sorry I am a layperson when it comes to photo programs but learn easily. Haven't taken many pictures in a decade due to depression but have recently come out of it and am now lost as far as how to use my greenscreen with PSP?

Thank you for any help at all, just point me in the right direction

[Zantara]

Be proud for coming out of your depression. You must have fought a long, very hard, battle.
The new PSP 2022 had a tool under Adjustment > Artificial Intelligence > Background replacer. It has 20 options, but you can choose your own as well. Wouldn't know for 2021 and lower, apart from the background eraser tool. But that takes lots of patience to erase pixel for pixel on the edges. You make the background transparent, that way and can than replace it with your own. Hope somebody here will know a better way.
Take care and believe in yourself.

[LeviFiction]

Not sure what you mean by using the background eraser "pixel by pixel" it's designed to be semi-automatic. Including demixing colors as it goes.

There is also the object extractor tool. This command opens a window where you trace the outline of the person or object, fill in the outline to define the area to keep and it attempts to separate the object from the background.

The new AI Background Replacer is only for removing people from their background, so less flexible but easier for a new user, and requires a bit more fiddling as you clean up the automatic selection with the refine brush.

All three are viable options. You can even just use the magic wand tool to select the green background and delete it

[Jean-Luc]

How can I replace a background on a green screen photograph?

Could you post an image here?

LeviFiction's suggestions are relevant.

[Zantara]

LeviFiction's suggestions are relevant.

They always are )