Do external authenticated users need Power App licenses?

[BPNJMC]

We are a small non-profit - a foundation running a community elementary school and 2 pre-schools.  I attended the Power Platform conference and got all excited about the possibilities... especially because of all of the COVID-related challenges we are facing right now due to remote/hybrid learning.  

We currently have an Azure subscription with a SQL database and a horrible c# web application running on an Azure web server.  Users from a few other domains  (the 3 schools and partners) log into our web app to read/edit data and view Power BI reporting.  I have to set up all users in our web app before they can login.

I want to replace that horrible c# web application with a Power App Portal so that users can read/edit data using Power Apps and Power BI. 

My Questions:

1. How many Power App licenses do I need to buy?  I will be the only person creating Power Apps.  Do I need to purchase licenses for all of the users that will login from the the other domains or only for me?
2. Is there an additional fee/license for Power Apps Portal?  Or is it included with the Power Apps license?
3. All users will have to authenticate before using the portal and they must be on our predefined list of users or invited (i.e. specific staff at our 3 schools or partners)  Some users should have restricted access to menu choices in the portal and some users need to have restricted access to data.  Can the user accounts and data security be administered in power apps?  Or do I have to set the users up in Azure Active Directory?

I'm trying to assign a cost for the Power Platform in a budget line for COVID related funding.  I've been reading pages for days and now I'm so confused about what I need to purchase (or not) and how much it will cost.  I'd be so grateful if someone could help me figure this out.  

Thanks,

JMC

[OOlashyn · Accepted solution]

Hi @BPNJMC ,

1. If you will be the only one to create apps you don't need to purchase licenses for anyone else. Portal is licensed on per login bases (see below). You can find pricing details here (just scroll a bit to Portal section),

2. Portal is licensed on per login based: 200 USD per 100 logins per month or 100 USD of 100k unauthenticated views. There is also a bigger volume pricing that you need to negotiate with Microsoft.

3. Access to the Portal is managed inside the CDS via Web Roles. You can find more about managing security on the portal in official docs here. All Portal users will exist as Contacts in your CDS. You can configure to use any 3rd party provider to login to Portal (like Facebook, Google, any OpenId Connect) or configure MS suggested way which is Azure AD B2C. You can find more about authentication here.