You're only allowed to build one app at a time

I create my first app and test it online already. Now I want to download the apk file for android but I get an error:
“You’re only allowed to build one app at a time. Your app Karate Prüfungsprogramm is waiting in the queue.”
I cannot fix it and can’t find any queue. Does anybody has an idea?

Could this have been caused because a build that you submitted has not finished processing yet? Your post was 7 hours ago - have you tried to create a build more recently than that?