Hi @ArturFerreira
As I understand, you have a Power Automate that creates events when a Trello card is created. Then, when you have an update to the event, you want the Trello card updated correctly?

If this is the case, you can do it easily in 2 steps. However, you need to save the ID information of the Trello card to be able to update it. You can add, in the first Power Automate, a list with the mapping from the event to the Trello card and then use that information in another Power Automate to update it.
If I have answered your question, please mark your post as Solved.
If you like my response, please give it a Thumbs Up.
Cheers
Manuel