This article https://help.nowtv.com/article/now-tv-box-stick-error-codes-messages states
"There's an issue with your payment -Go to NOWTV.com/account on a PC or Mac, and make sure your payment details are updated correctly ."
Hi yeah I have reset the payment details and still the issue is there.
Basic TS Steps:
1. Go to NOWTV.com and click Sign In
2. Click on My Account on the top right of the page.
3. Click on Update Card details.Click on Change Card Details.
4. Enter your updated card details and billing address.
5. Click Update.
Make sure the card is activated, make sure the billing details are 100% correct, letter for letter, format for format. Do this on PC is possible or if on mobile, using chrome, click the settings icon and then 'Request Desktop Site'.
Let me know how it goes. Thanks for the tag btw @robert1997