Force screenshots to sd
How do I do that?
On Linux proper, this is a snap--so it should be on Android too, right? Well...apparently not. I'd never given it any thought, as the default location is okay for me, plus I clear out my screenshots frequently, moving them to my networked computers. (Where, I realized recently, I -don't- clear out unneeded stuff frequently--I found screenshots from 10+ years ago!
)
Oh, yeah, your question: I don't think there's a setting to change the default location.
But! You can try various apps, like this one, cleverly called
Screenshot, which says: "You can specify the folders which the screenshots will be saved as images." I don't know, but kind of doubt, that includes SD card locations. I can't test it, so you're on your own.
There are many other screenshot apps, so you might want to look through some of those.
How do I make sure all previous go there?
Previous, as in already existing? You'll have to move those yourself. Any file manager should be able to do that. You just select the files or directories you want, then move them to their new location. If you need help, just ask.