Yes, you can. You can switch to logging in with Google or Apple at any time, even if you already have an existing Campercontact account.
Linking to your existing account
The system recognises you based on your email address. If you use the same email address with Google or Apple as your Campercontact account, everything is linked automatically. Your PRO+ subscription, purchases, favourites and routes will all be available as normal.
Note: if you use the "Hide my email address" option with Apple login, the system will create a new account and your purchases and settings will not be available. Always choose "Share my email address with Campercontact" to avoid this.
Switching back to email and password login
You can always do this. Use the "Forgot password" option to set a new password, then simply log in with your email address and password as usual.