How to use PDF templates in dolibarr

Hi everyone. I am developing modules, and I need to create a PDF for them. I am not well versed on the code, but looking at the code it seems like there is opensource libraries like TCPDF and TCPDI that in turn use FPDI. I think that FDPI is a library that allows you to import existing PDF’s and breaks them down as a template, then you can write to them, and then export your own information onto this PDF template.

Am I correct on this?

If yes, I have been trying get this to work but am not sure how. It seems like there is something to do with SPECIMEN.pdf in your documents/mymodule directory. But that doesn’t seem to work.

Does anyone have some tips or directions on importing your own PDF templates, or if it is even possible to do this?