Back in 2017, PayPal and Google Pay announced their integration. Since then this greater option was only available for the people in the US. And now as per the latest report from the below source suggests, the rollout for Germany has also begun.
As per the report suggests, some users in the country have already started seeing the option to PayPal to their Google Pay accounts. It’s rolling out in phases, so it might take time to reach you so be patient.
And it’s also come to hear that it only works if you link your bank account to PayPal — sorry it’s a no for the debit/credit card.