In retrospect to the worries we had before our recent trip...
It was actually quite easy.

Docs&Travel Authorization + antigen test results (US)
Ecopy+paper copy + upload to airline. (Upload everything you can)
but
Never had to show anything but passports.. already had boarding pass on app.

Arrival =
Arrived and out airport in 25 minutes. It was a light day but full flight...

No worries
Have a great trip