Scenario
Now, let’s say you have a premium workspace, with one or more apps published in there, and you want to invite an external user who is not in your domain as a guest. If you don’t have a premium per capacity workspace, then the user needs the appropriate premium per user workspace.
In general, PowerBI lets you share to guest users in your organization’s Azure Active Directory (Azure AD). You can't share to external users who aren't guests in your organization. Therefore, you need to create a guest account in your AAD account. They will also need to then be licensed for a PowerBI Pro license so they can receive the link and access the reports.
Disclaimer: The authentication is done by an external system (like Google). Microsoft only takes care of identification and authorisation (determines access rights). Assess the security implications carefully before using this approach.
Links and references
Here is the link which talks about various scenarios.
Additionally, to share it with any Gmail or personal Id, you could try this, but eventually the user need to create a AAD account.
Procedure
Here are the steps to follow in order to invite a guest and share one or more apps in a Power BI tenant.
Step 1: From the Users > Guest Users page, click the Add a Guest User button
Step 2: Select Invite user for the template, and then fill out the required details such as Name, Email Address, etc.
Step 3: On the external user’s side, an invitation will be received. Accept the invitation, login to your account (if necessary), and click ‘Accept’ on the permission prompt that comes up.
Step 4: Upon doing this, you will come to a screen that says ‘Apps’ but does not contain anything. This means the external user is now logged in.
Step 5: Next, on the admin’s side, select the guest user and manage which licenses to give to the user. In this case, we will go with the free license.
Step 6: After that, navigate to the page shown to access all the apps currently published, and click on the one you want to share.
Step 7: Then, click on the edit button as shown once the app is opened and Click the Update App button.
Step 8: Here, navigate to the Permissions tab in the page you land on, and then in the Access section, select Specific Individuals or Group, and then enter the email addresses of the external users you want to share the app to, then click Update App.
Step 9: Once you see the Successfully Published prompt, copy the app link given and share it with the external users.
Step 10: On the external users’ side, click the link provided by the administrator, and then follow the prompts and log in. Note that you will not be able to log in directly via the app.powerbi.com portal. You will have to use the app link provided or you will have to use the URL with the customer tenant id (example below)
Example: https://app.powerbi.com/home?ctid=XXXXXXXXXXXXXXXXXXXXXX
Results
You will now be able to view the app using the external user ID.
