If you have to get a COVID-19 test for your flight, download whatever app the airline suggests, and upload your test results (and/or vaccination record).
"COVID has really slowed things down at most airports. Getting everything done at home before you arrive at the airport will save you big time. Recently, I didn't download or upload my test results and vaccination record to the airline app, so I had to wait in a very long check-in line.
At this point, every airline seems to have their own test and vaccine verifying service. American Airlines uses VeriFLY, United Airlines uses Travel-Ready Center, and many international airlines are currently testing the IATA Travel Pass. With these apps, you can see what documentation you need to fly and you can get it verified in advance."
Yeah, some are only 10kg!
There is no step 2.
Enjoy your flight.