First of all, kindly be reminded that there are 3 different subscription platforms, which are Nüli Website, App Store, and Google Play. It is highly important that you follow below steps and make the change via the same platform that you chose for subscription originally:
💁🏻 I subscribed via Nüli Website
Log into Nüli Website-My Account.
❗️Please make sure that you log in with the same method as you used, while making registration on Nüli website, so your account can be synced correctly. (e.g. You registered "with Facebook", you will have to login the app "with Facebook" as well.)
Go to the "Membership & Billing" section, then click on [Manage] next to the payment method.
Click on [Add card], then enter the credit card information you want to change, then click [Save card] and you're done!
💁🏻 I subscribed through App Store (iOS)
Go to Settings on your cell phone or tablet.
Tap your name, and then tap "Payment & Shipping". You might be asked to sign in with your Apple ID.
From here, you can do these things.
Add a payment method: Tap "Add Payment Method".
Update a payment method:
Tap the "payment method", then edit your information. You might need to enter the security code that's printed on your credit or debit card. If you use the card with Apple Pay, go to the Wallet app to edit the card information.
💁🏻 I subscribed through Google Play (Android)
Go to Play Store on your cell phone or tablet.
At the top right, click your profile icon.
Select "Payments & Subscriptions" > "Payment Methods", and then select "Edit Payment Method".
Under the payment method you want to edit, click "Edit".
Make your updates and click "Update".