Here is a totally different approach.
It is possible, because in recent times a series of new conversion paths were opened by Pandoc's newly acquired capability to read ODT files.
When Pandoc reads in a file format, it converts it into an internal format, "native" (which is a form of JSON).
From its native form, it can then export the document into a whole range of other formats. Not only PDF, but also DocBook, HTML, EPUB, DOCX, ASCIIdoc, DokuWiki, MediaWiki and what-not...
Since here the wanted output format is PDF, we have another choice of different paths, provided by what Pandoc is calling a pdf-engine. Here is the list of currently available PDF engines (valid for Pandoc v2.7.2 and later -- previous versions may support only a smaller list):
pdflatex: This requires LaTeX to be installed in addition to Pandoc.
xelatex: This requires XeLaTeX to be installed in addition to Pandoc (also available as an additional package to general TeX distributions).
context: This requires ConTeXt to be installed in addition to Pandoc; ConTeXt is available as an additional package to most general TeX distributions).
lualatex: This requires LuaTeX to be installed in addition to Pandoc (also available as an additional package to general TeX distributions).
pdfroff: This requires GNU Roff to be installed in addition to Pandoc.
wkhtml2pdf: This requires wkhtmltopdf to be installed in addition to Pandoc.
prince: This requires PrinceXML to be installed in addition to Pandoc.
weasyprint: This requires weasyprint to be installed in addition to Pandoc.
There are some more and newer PDF engines now integrated into Pandoc, which I have not yet used myself and which I currently cannot describe in more detail: tectonic and latexmk.
WARNING: Do not expect that the appearance of your original document will be identical in all the PDF outputs to the print preview or PDF export of the ODT! Pandoc, when converting does not preserve layouts, it preserves the contents and the structure of documents: paragraphs remain paragraphs, emphasized words remain emphasized, headings remain headings, etc. But the overall look can change considerably.
Example commands
pdflatex:
pandoc -f odt -o mydoc.pdf mydoc.odt --pdf-engine=pdflatex
XeLaTeX:
pandoc -f odt -o mydoc.pdf mydoc.odt --pdf-engine=xelatex
LuaLaTeX:
pandoc -f odt -o mydoc.pdf mydoc.odt --pdf-engine=lualatex
ConTeXt:
pandoc -f odt -o mydoc.pdf mydoc.odt --pdf-engine=context
GNU troff:
pandoc -f odt -o mydoc.pdf mydoc.odt --pdf-engine=pdfroff
wkhtmltopdf:
pandoc -f odt -o mydoc.pdf mydoc.odt --pdf-engine=wkhtml2pdf
PrinceXML:
pandoc -f odt -o mydoc.pdf mydoc.odt --pdf-engine=prince
weasyprint:
pandoc -f odt -o mydoc.pdf mydoc.odt --pdf-engine=weasyprint
Above commands are the most basic for the conversion. Depending on the PDF engine you pick, there may be many other options possible to control the appearance of the output PDF file. For example, the following additional parameters may be added to all those paths routing through LaTeX:
-V geometry:"paperwidth=23.3cm, paperheight=1000pt, margin=11.2mm, top=2cm"
which will use a custom page size (a bit larger than DIN A4) with margins of 2cm on the top edge and 1.12cm at the other three edges).