Best way to share report to external users?

[Anonymous]

I have a Power BI report with multiple pages that needs to be accessed by people outside of the organization. I need help figuring out all my available options. I cannot publish to web, as this has sensitive information. I plan to use row level security to lock down the data based on Customer, so cust1 will only see data related to cust1. Nobody else should ever be able to view this report except for the users I designate....cust1, cust2, cust3, etc. 

The option I've tried is setting up a customer with an email:  cust1@mycompany.com.  I then shared the report with them.

The issues I ran into are:

1. When I logged into Power BI service with my cust1 account, i opened the shared report and it gave me an error saying I needed Power BI Pro to view it. I thought sharing/viewing within service is free?
2. having a mycompany email gives them access to Office 365. I dont' know enough about O365 to limit them to only Power BI, none of the other apps nor our sharepoint site.

Can somebody help me figure out the available options?

[Greg_Deckler]

You should be able to share with the external email. Sharing requires a Pro license or Premium capacity.