You'll not receive any invoices to pay a license if you are using the Power Apps or Power Virtual Agents inside the Microsoft Teams. Today, the license is purchased if you are using the Power Virtual Agents on the web (https://web.powerva.microsoft.com/) but if you are using inside the Teams no need to worry.
The PVA for the web license is purchased by the tenant and not by user or bot.
And you can manage your environment using this link: https://admin.powerplatform.com
Thanks,
Prasad Das
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