"Your Payment method is not valid in this Store"

You need to verify your payment information:

Sign in to your Apple ID account page and edit / update your Apple ID details.

https://appleid.apple.com

On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.

Or -> Change, add or remove Apple ID payment methods

Change, add or remove Apple ID payment methods – Apple Support (UK)

• Add first the new card, then remove the old one.

See also -> Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

Add money to your Apple ID balance

Add money to your Apple ID balance – Apple Support (UK)

Additional:

Check & optimize -> Wi-Fi.

Charge the battery > 70%.

If you're still unable to update your payment method, Contact Apple Support.