Communication using Github Actions between two related repositories

I'm looking for a way to use Github Actions and establish communication between two repositories that are related to each other. I need help since I have never done this. The logic would be like this:

1. Repo A needs to deploy to some Cloud cloud (AWS, GCP, Azure, etc.), based on functional requirements that need to be fulfilled. But it does not have that code logic or the necessary parameters to execute that deploy, that is what Repo B is for. ** Github Actions would come in here **

2. Repo B if it has this code logic and parameters necessary to be able to make this deploy request, then it **occupies Github Actions???** in some efficient and precise way. Capturing repo A requirements.

3. Repo B performs the action and reports the incident if it was satisfactory or if there were errors. The success or error message is reported to repo A, for adjustments and further testing.

Has anyone already done this before? What would be the most efficient way to do it? And the most correct? I spent hours with ChatGPT but I had no success.

Thank you!