I used photopea, and whenever i try to save an svg, upload to photopea to add another image with the svg, save it as an svg and then try to upload to scratch, the svg image does not show at all. I am not an expert but I am having problems with using photopea/scrarch

I tried to change the resolution dimensions

I tried to save the non-svg parts on scratch by converting it to vector to save it as svg, then upload it without trying to “rasterize” it, and still nothing shows up.

So if I understand correctly, you:
Export svg from Scratch
Edit svg in photopea
Import svg in Scratch

Have you tried opening the svg in your browser? This can narrow down where the problem lies. If you can properly view the svg in your browser, the problem probably lies in the editing program adding something to the svg that Scratch can't display. You can open the svg in a text editor (notepad) and take out parts of its contents to see if that helps.

i try to do the same thing
export from scraatch
load to photopea
import to the user image
and it doesnt work