2. Keys lost so far

Hello, I wanted to have an axis measurement and track adjustment done, since I had recently also had the left crossbar changed. Now the problem, in the workshop where I had the track adjustment done, cannot find my replacement key, which I had left there. But since I am dependent on a 2nd key, a 2nd key must come back again, so that my brother can always use the car without any circumstances. Now my question to the Community y, how would you proceed in my situation? The whole thing happened yesterday and so far the workshop has still not notified.