If you are having trouble accessing the iTunes Store and / or App store (on both iPhones / iPads and Macs) Well, you're not alone.
As we can see on Apple's "System Status" page, services are failing right now. According to the company, “some users” are being affected and unable to make purchases at Ma's multimedia stores (iTunes, App and iBooks Stores).
According to MacRumors, there are also users complaining about Apple Music and other services, although Apple does not list any problems with them.
Developers are also being affected, more precisely with App Store Connect (where all applications are managed) and the TestFlight testing platform.
We'll see when all this returns to normal.
Update by Rafael Fischmann 5/8/2019 15:45
At least the two developer-related services (App Store Connect and TestFlight) are back to normal, according to Apple.
Update II 5/8/2019 16:15
Apparently the services are back to normal.