Automated PDF Generation

You actually purchase the A SKUs through the Azure portal. see https://learn.microsoft.com/en-us/power-bi/developer/embedded/azure-pbie-create-capacity?tabs=portal

And there are details here on how to pause/start an embedded capacity https://learn.microsoft.com/en-us/power-bi/developer/embedded/azure-pbie-pause-start with links to ways to automate this.

Once you have created and started the embedded capacity you then need to go back to Power BI and into the setting for your workspace in the Premium setting set it to use this A SKU. Note that once you do this the embedded capacity needs to be running for the reports to work.

The standard P SKUs are really aimed at large enterprises with 500 or more report viewers. For smaller organizations with a monthly report burst like this the A SKU should be more cost effective. The note here https://learn.microsoft.com/en-au/power-bi/enterprise/service-admin-premium-testing#purchase-a-skus-for-testing-and-other-scenarios says that the A SKU gives you all the features of a standard premium capacity, but without the unlimited sharing (so all your users will require Pro or PPU licenses, but it sounds like you have these already)