How do I add external users to MS Project for the Web project?

[BrianRMI]

I am trying to migrate from Asana to Project for the web but I have some questions/issues that I can't seem to find answer to.

1. I started with the trial and then had Planner P1 licenses added to my M365 licenses and assigned myself one (yes, I am the M365 admin, so can have whatever permissions I need). Project for the Web still shows "Your trial has expired" and I don't know if that's an issue or just an annoyance.
2. I can't seem to add seem to add an external user to the project. When I click "Group Members" and type in an external address to add, it shows "No results found." I have read that if my Entra ID permissions allow for ext. users, I could simply add them to the project by adding the ext. email to a group assigned to the project. But, I can't seem to do that. Do I need to first create an M356 group and try to add the ext. user to it, then assign the group to the project?
3. When creating a new Group from within a project, there's a "Classification" field that I can't find documentation about. The field is required but it's empty and there is currently nothing to select. I'm guessing this field is used for data privacy (e.g., internal or external policies) but don't know how to configure it.

I hope others can also benefit from this thread. Thanks for any valuable input!

Brian

[#2]

BrianRMI --

Did you read the following Help article from Microsoft:

https://support.microsoft.com/en-us/office/let-guests-see-your-project-in-project-for-the-web-81e1c2....

Let us know and we will try to help you.

[#3]

Yep, I did reference that article, Dale, but can't seem to figure out how to find the "project's Microsoft 365 Group" to which I need to try and add the external users. Assuming this means Project for the Web creates an M365 Group for every new project (seems like MS creates a new M365 group for just about everything), do you know how one finds this M365 group? I tried to find it through the settings of said project, but haven't found it yet.