An update is available for the BIM Track PDF printer when using the latest version of the add-in (see Download the PDF Printer Update for BIM Track for Revit v1.63).
The BIM Track PDF printer is required to be able to publish sheets to BIM Track.
During the add-in installation, there is a dedicated page that prompts you to download and install the PDF printer separately.
If you do not install the PDF printer during the initial installation of BIM Track, you will be prompted to install it when you use the Publish feature of BIM Track in Revit.
In the Publish to BIM Track dialog > Publish PDF Sheets portion, click Download. Once the installation is completed, click Check again.