One question at a time, in the order that actually solves things. Tell us your handset first and you'll only ever see menus that exist on it.
Do not delete the eSIM profile
Most travel-eSIM QR codes are single-use. Once you install and then delete, the activation code is spent and cannot be re-scanned. If you do need a fresh install, ask us for a new code first.
Every fix that follows is the same idea on any phone, but the menus live in different places. Tell us the handset once and you'll only ever see paths that exist on yours. Android answers show the Samsung and Pixel layouts; phones from Xiaomi, OnePlus, Motorola and others sit somewhere between the two, so search your Settings app for roaming, mobile data, SIM, or APN to reach the matching screen.
Every fix in this flow comes from our written guides, which cover the same ground with more background.