Annoying iTunes Pop-Up

I keep getting a pop-up on my phone (iPhone X, latest iOS 13.1.2), saying "The iTunes Store is unable to process purchases at this time. Please try again later" however, I have not tried to purchase anything from the iTunes Store today, and the previous purchase I made was successful, it seemed to pop up for no reason as I had not been on the iTunes store when it started popping up. I have tried to 'turn it off and on again' method, and it was fine for half an hour until it popped up again. Thank you to anyone who responds!