You can complete the setup in 10-15 minutes by following the steps below.

If you are not using Yoom, please register for free from here.
If you are already using Yoom, please log in.
How to Connect Trello and Zendesk with Yoom
Please register your My Apps to connect Trello and Zendesk with Yoom.
Registering My Apps first makes it easy to set up automation.
First, register My Apps for Trello.
Yoom's help page describes the registration method, so please refer to it and register.
Next, register My Apps for Zendesk.
*Zendesk is an app available only with the Team Plan and Success Plan.
Please note that if you are on the Free Plan or Mini Plan, the operations and data connections of the flow bot you have set will result in errors.
*Paid plans such as the Team Plan and Success Plan offer a 2-week free trial.
You can use apps that are subject to restrictions during the free trial.
This is also described on Yoom's help page, so please set it up in the same way.
How to Update Zendesk Ticket Status When a Task is Completed in Trello
To set up automation, please click "Try it" on the banner below.