Hello and welcome Alessia,
The short answer to your question is: No, you can't have two actions with the same Invocation Name, especially when one is deployed.
Let me briefly walk you through you my own experience: I also have two projects for one Action, one is for testing and the other is for production. When I try to use the same Invocation Name first error I encounter is in the panel:
Could not reserve your pronunciation 'Action Name'
But I thought; "But it still saves the details. I'm not going to deploy it anyway so I don't need it to be reserved." But when I try to test the Action in the Simulator, I encounter a second error:
You cannot use Actions deployed by others in the Simulator. If you want to try the Actions, use Google Assistant on your phone or other compatible devices.
In short, Simulator thinks that you're trying to invoke the Action that's on production and forbids it since it's not connected to your current project.
How Did I Get Around This?
It's quite simple actually: I named the test version of the Action "Action Name Dev". Since I won't ever be deploying this version, it's not a problem at all. I only use it to invoke the Action, it doesn't affect the conversational experience or the code.
If you have any other questions, go ahead and post it.
