Secondments

Dear Brian, dear Pablo,

Do you know if in Germany it's possible to get a daily allowance for the secondment? In my case (Leibniz University Hannover) my working place was a changed to the place of secondment. When I returned back my Professor told me that they have to pay me a daily allowance but asked me (and my collegue) to refuse from it. I didn't get the money.

Is that obligatory in Germany to pay the daily allowance or not? Could I still ask for that money?

Thank you in advance for any advise!