Trello didn't send x-trello-webhook header first time.

[Александр Смирнов]

[Garrett · Accepted solution]

Hi @Александр Смирнов 

This would be a really great question to share in our developer community.

We have a few Trello Engineers that are active there, and they or some of the community champions would be happy to give some guidance for more advanced topics like these.

https://community.developer.atlassian.com/c/trello

[Александр Смирнов]

My colleague already gave me one of the reasons:
"Trello does not sends x-trello-webhook on webhook setting because user could write wrong hook url. Subsecuent requests contains this header"