Fachabitur certificate?

Hello,

I have the written part of the Fachabitur (leaving after 12th grade). I am currently in my third year of training as a warehouse logistics specialist. After completing my training, I completed the practical part of the Fachabitur, thus also the Fachabitur in its entirety.

How do I get the certificate or confirmation that I've passed the Fachabitur (university entrance qualification)? Does the vocational school or the Gymnasium (high school) where I previously attended high school do this?