How can M365 Copilot use On-Prem File Storage as a sourse of microsoft graph? And it's security?

Hello this is Johnny,

I have two questions as below.

1. Is it available to use microsoft copilot with On-Prem File Storage?

I have searched about it, and found that configuring Microsoft Graph Connectors can help Symentic Index to index On-Prem File Storage.

Is this correct?

2. If yes, how can I restrict access to On-Prem File Storage, for On-Prem File Storage does not have any permission aligned with AAD User and Group?

Thank you in advance.