Hi @stefan, welcome to the Forum!
I think your issue might be similar to the one described here about unexpected keyword argument 'session'.
If that’s the case just make sure to pip install qiskit_ibm_runtime==0.29.0. Then you can create a device as follows:
import pennylane as qml
from qiskit_ibm_runtime import QiskitRuntimeService
# get backend
QiskitRuntimeService.save_account(channel="ibm_quantum", token=token, overwrite=True)
service = QiskitRuntimeService(channel="ibm_quantum")
backend = service.least_busy(operational=True, simulator=False)
# initialize device
dev = qml.device('qiskit.remote', wires=127, backend=backend)
The code above will choose the least busy available backend.
Let me know if this is what you were looking for!