Currently, PDF generation/email PDF capabilities are only available in the Sales module. I believe such generic productivity features should be available to all entities including custom entities in Power Apps, not just for Dynamics 365 Sales app.
I think the feature you are searching for is available in Power Automate via the Word Online Connector.
Unfortunately, this is a premium connector, so it's not free to use.
However, it allows you to auto-populate Word documents and to generate a pdf out of a docx file.
@simb55 Thanks for the reply. But I don't think it supports direct email pdf functionality. First, you need to generate the word, and pdf and email it. What we are requesting here is the functionality Microsoft has already introduced in the Sales module, we see great value for it in other modules as well.