I just Googled “SVG qr code generator” and found this: https://qrplanet.com/qr-code-generator-svg
SVG is a vector format so you can expand or shrink it without losing quality. So you could maybe bring it to 5000x5000 with illustrator/krita and then export to a raster format (jpg/png) so you can modify it how you want
Oh my god, how could I not have seen that. Now the icon makes sense too.