The Gitea installation process as currently described leads to non-working webhooks with the following error showing up in Gitea logs:
Delivery: Post "https://drone.123.com/hook?secret=HMKLFV47c1kJ78QyVez6RHcxPJAHI6TB": dial tcp 192.168.1.10:443: webhook can only call allowed HTTP servers (check your webhook.ALLOWED_HOST_LIST setting), deny 'drone.123.com(192.168.1.10:443)'
This issue and its solution has been described here before: Gitea Webhook Change
The Drone installation docs for Gitea should mention this.