Nitrokey and U2F and WebAuthN

I apologise in advance if this is too basic, or the answer exists on here somewhere. I am trying to use my nitrokey pro for 2fa on a bitcoin selling site (a large reputable one) but I can’t get it to register properly. The site says it works with keys that support U2F and WebAuthN. I think nitrokey supports U2F?
I am following instructions to insert the key, allowing it to proceed when asked, but it fails.
I have tried with the key locked and unlocked to no avail. Can anybody advise me on what l might be doing wrong?
Big thank you for any help.

Hi @barnoo!

I am sorry, but at the moment Nitrokey Pro does not support FIDO U2F / FIDO2 / Webauthn. We have separate products for that: Nitrokey FIDO2 and (older; now discontinued) Nitrokey FIDO U2F.

Thanks for that. Its good to know that I dont have to buy a yubikey. Ill grab a fido2.
Good to know.