[BUG] Unclear error toast when trying to add a trigger before configuring a query while creating a monitor

[vikhy-aws]

What is the bug?
When creating a monitor, adding a trigger before configuring the query pops up an error toast with an unclear description.

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Go to Create Monitor
2. Click on Add Trigger button
3. See error

What is the expected behavior?
There can be two expected behaviors:

1. The Add Trigger button is disabled until the query is configured.
2. When the Add Trigger button is clicked, the error toast must show a clear description saying "You must configure index and query"

Screenshot of the issue