Clarification on "Embed for customers"; PHP-Example

I´ll use PowerBI as a glorified DataViz-Tool.
Szenario is we want to embed reports for (external) customers on a website so that they don`t need a PowerBI-Account to log in. We`ll publish a free variant as well as an extended version on our website - but only "premium"-customers will be able to expand certain visualisations.

I need AAD and an AzureSKU.

Two questions:

A) do I understand correctly that the report will only be accessible while the SKU is running?

B) do you know of an example how embedding & authentification is done via PHP?