Not being in possession of vaccination evidence which satisfies the spanish requirement, I obtained test certificates online and filled in the form to produce the spanish locator doc with its QR code.

They were not checked before boarding, on a lowcost airline, but they (or vaccine evidence) were the first thing demanded on arrival at BCN - before passports - and people without them were refused. I didn’t see what the eventual fate of the refused was.

However, the spanish locator forms with their QR codes (or vaccine docs) were not scanned or examined in any detail. We’d have been fine with anything that looked vaguely correct at a glance.

The lowcost didn’t mention masks and v few people bothered. No mask harassment by airport staff either.