could not run legacy post zone sub request against new zone products: failed to update user subscription: failed to apply object products: You cannot add or modify subscriptions or services until the outstanding balance is paid. You should be able to do so in your Billing page.
What is the issue you’re encountering
i can’t add website domain on cloudflare dashboard
I should point out that this is not a billing problem, because on my main account, I have no unpaid bills and no paid subscriptions. I tried to add my site to another account that had just been created, with no subscription and no invoice, and I have the same problem.
This is not related to a specific domain as I bought 3 on Namecheap and all 3 have the same error when I try to configure them by choosing the free plan.