If the PDF export fails, ensure that Chrome headless works fine. You can test that on the CLI like this:
google-chrome --version
If you have a local installation, you could also try to force temporary local storage. (Available in the module's configuration) This will store the content to print on disk, instead of transferring it directly to the browser. Note that for this to work, the browser needs to be able to access the temporary files of the webserver's process user.