These tests are fun, but I wouldn't consider them scientific.
As a person who has taken hearing tests, they put you in sealed rooms with noise isolating rubber domes on your ears. And for general listening, they rarely test over 4-6 KHz. That is considered the top end of normal listening. So for those commenting about legal deafness, please do a bit of research and save us from reading online speculative banter.
Also, I see many are using open headphones for these tests. Not really possible to do an accurate test with open headphones. Ambient dB is probably around 20-40 dB for you. Meaning, we all get used to ambient noise. And for those who have tinnitis, well, they are always hearing a ringing noise, so they probably hear ambient noise even when it doesn't exist. Ambient noise can either boost the sound or offset it. Kind of the way noise cancelling headphones work, if your ambient noise oscillates off phase as one of the tones in these tests, it may actually be cancelling out the tone.
So I wouldn't be too nervous if you have a hard time hearing these frequencies. But they maybe a good indicator you need to go see an ear doctor. Me for instance could hear 21kHz like it was 14kHz. The volume was ear piercingly loud. But 20kHz was a faint and barely audible. 22kHz was also very faint. I'm a weird nut though, I'm that 1% that can hear dog whistles. My friend has a ski cabin in Vermont, and he has a dog deterrent outside his house. It's basically a supersonic speaker that is designed to irritate dogs and to prevent them from entering their premises. Many are probably familiar with these devices. They operate at various frequencies, but generally at or above 20kHz. Of my friends, I am the only one who can hear the sound coming from it. I guess it also makes sense that of my friends, I'm the only audiophile.