Web app - can't login

Hi everyone,
I pre-ordered the game specifically to get early access, and I'm playing through Amazon Luna. However, I'm unable to log into the EA Web App it either doesn't recognise my account or gives me an error.
I’ve double-checked that my EA account is linked to Luna, and I’ve restarted everything, but no luck. Is there a known issue with Luna users accessing the Web App? Or is there something I need to do to activate early access properly?
Any help or guidance would be appreciated—thanks in advance!