Hi @reutkeller,
From the code that you posted, it seems that you are specifying your INSTANCE_ID to be an empty string, which would then trigger your config variable to be None.
If when you print sentinelhub.config it is correctly setup, then you can just delete this part:
INSTANCE_ID = '' # I have already put instance ID into configuration file at the beginning so left it empty as required
if INSTANCE_ID:
config = SHConfig()
config.instance_id = INSTANCE_ID
else:
config = None
and write the following:
config = SHConfig()
To check if the credentiials are correctly assigned, you can also add:
print(config)
Maxim