As someone who lives in Germany and has recently acquired his Crypto.com Visa-Card (virtual for now), I had just learned, that you cannot link it directly with Apple pay.
And when I researched into it, it apparently isn't just a problem people in Germany might face. The EU hasn't allowed for implementation of above mentioned card yet, so Apple Pay will just tell you that "the selected card is not yet supported in your region" and that's it.
Luckily there is a pretty easy workaround for this, which is called "Curve".

Curve is a app avaible for iOS and Android, which has the ability to incoporate and manage your virtual debit- and creditcards. Besides that, it also allows you to store your loyalty cards of different stores for easy access.
Setting up the Curve app took me about 10 minutes. You will be asked for your residential information and some form of identification (Passport,driver, etc.)
After you successfully opened your account, you are given the option to connect a card to Curve. Here is where you have to connect your Visa card with your Curve account (It is very easy and straightforward).
After that, you can either go back to the Wallet-App or connect the Visa-Card directly from the Curve App to Apple Pay (again very easy and straightforward).
Congrats, you can now use your virtual Crypto.com Visa card through Apple Pay.
One important note to mention however: Make sure you have the Visa card selected in the Curve app, so it gets used as the primary form of payment.
The standard version of a Curve account is free to set up and use, though they do have tiers to which you can upgrade to.
P.S.: It seems that upon creating a account, Curve automatically sends you a physical card. However, since I have not received it yet I can't give my opinion on that.
For more information, you can visit the Curve website here.
I hope you enjoyed reading and have fun gaining your payback rewards!