Copilot agents data authority

Question

Hi, We are currently trying to develop an internal agent for our employees to help them with the data from our organization, to build this custom agent, then we will link it directly to our data verse. I have 2 main questions regarding this:

1- Does the employees need to have licenses to use this agent to retrieve data from it?

2- If the answer for previous question was no, then is there a way to ensure each employee could have the right access to the right data (Logistics have only access to Logistics data, and does not access financial data)?

3- Is there a way to prevent public access to these agents? Only sign in before using these agents?