Are there any limitations to external access to Microsoft App?

Question

We currently do not allow access from external resources to the company M365 resources (Teams, Email, etc.). With the AVD Remote Desktop client being replaced with Microsoft App it looks like if you want to be able to use this from an external resource (Home PC) you would need to be able to log into your company M365 or this will not work for you? Currently we use the AVD remote desktop client with MFA and that works but when trying to test with the new Microsoft App from home you get the "You can't get there from here" screen. Thats because we block that access with Conditional access for external users connecting to M365. Basically, I was looking to see if this is the only way you can connect with the new client (Microsoft App) and is there a license limitation to connect or will like a basic F3 license suffice?