insufficient_allowance — top-up not possible

The order was not created. Body: reason: "insufficient_allowance" — and, unlike payg_topup_required, it does NOT contain the top-up fields (shortfall_*, quote_token, expires_at).

The subscription quota was not enough, and pay-as-you-go is disabled for this service (Service.payg_access = disabled). That is exactly why you get a refusal instead of a top-up offer: there is nothing to top up with and nowhere to top up — no top-up mechanism exists for the service.

This is a dead end on your current plan: neither a retry nor confirm_payg_topup will help — the server simply ignores the latter field. There are three workable options: wait for the quota to renew in the new billing period, change your plan, or reduce the size of the order so it fits into what remains.

GET /subscriptions — items[].tokens_remaining shows how many tokens actually remain; cut the text to fit that amount.

• payg_topup_required — when a top-up is allowed
• limit_exceeded — the neighboring subscription limit
• Guide: LMC, quotas, and PAYG
• GET /subscriptions
• Change plan