Contactless payment by card is mandated going forward:
https://www.fleeteurope.com/en/new-energies/europe/article/f...
So you won't have to sign up for anything else.
https://www.fleeteurope.com/en/new-energies/europe/article/f...
So you won't have to sign up for anything else.
But there are also services like ChargePoint which unify the payment systems for numerous networks (certainly including Eon and Shell).