Telegram error 400: Bad Request: bad webhook: HTTPS url must be provided for webhook

setWebhook was called with a URL that does not start with https://. The hosted Bot API refuses plain HTTP webhooks outright; this is documented under setWebhook and in the FAQ. The only way to use an HTTP webhook is to run your own local Bot API server, which explicitly allows it.

All bad webhook: descriptions share the same shape: the prefix identifies the setWebhook validation stage, and the remainder names the rule that failed. Sibling messages include port restrictions and host resolution failures, covered in their own entries.

Because the webhook was not set, your bot will continue in whatever mode it was in before (polling, or the previous webhook). A common follow-on symptom is a bot that 'works locally with polling but not in production' because the production setWebhook call silently failed in a startup script.

{"ok":false,"error_code":400,"description":"Bad Request: bad webhook: HTTPS url must be provided for webhook"}

Fail deployment when the webhook URL is not HTTPS, and log the setWebhook response body instead of discarding it. Treat getWebhookInfo as a health check that runs after every deploy. See Telegram bot not responding for the full webhook diagnostic.

The scheme rule sits alongside the four-port rule (443, 80, 88, 8443) and the certificate requirements, all tabulated under webhook limits. Once registration succeeds but deliveries fail, the diagnosis moves to your endpoint; that side is covered in the webhook debugging guide.