type: https://unprofane.com/docs/errors/subscription-required, status 402.
What to do
Live and publishable keys answer only on a plan. An account with no plan (a new one, or one whose plan was cancelled, went unpaid past the grace or whose research grant ended) has test keys only, 100 checks a day. Choose a plan on the pricing page or the dashboard’s billing page, from $9 a month; the same keys answer within a minute of the merchant’s confirmation. Until then, build with a test key.