Whitelabel APK not working

I white-labeled an app couple of days ago.
I got the Android APP download url and all.
The download url was working for couple of days and then it stopped working.

Note : I have not yet uploaded the apk to playstore.

It gives the attached error now while trying to download the app through that link.

Is there something else I am supposed to do or is this a potential issue?

Please contact Support for help with this.