Philipp, In SAP transaction SE37 you can see FM BAPI_PRICES_CONDITIONS is not remote enabled. This is an SAP standard FM which means its probably identical to the SAP instance you are connected to. Do you have access to SAP? You will need to register the object with SAP in OSS which will give you a change key for them to be able to mod it or you can create a "Z" FM that you set to remote that simply calls BAPI_PRICES_CONDITIONS.

When you going into "change" you will receive a screen like this where you would enter the access key you get from OSS

Let me know if you anymore assistance.