Which pdf library for used ODT

I notice dolibarr is using fpfd and tcpdf. Can someone confirm which is used when converting the odt files to pdf ? I have googled but cant find any information on how this works.
Thanks
Paul

To build odt, library used is odtphp
To build pdf, library used is tcpdf + fpdfi (that is not fpdf)

Hello I have read documentation on odtphp I can see how you generate the pdt templates - nice idea.

However I am confused about pdf generation you are using

However it seems fpdi supports pdf as template not ODT ?
Thanks
Paul