HP will not show any driver for your device. Instead, they show the HP Easy Start v2.9.0.180 application which will attempt to locate any current driver update for your printer once it is installed. Also, on that HP site, one must select macOS, then the version (10.14), and finally click the Change button to pull up anything for Mojave.
Do you have HP Easy Start v2.9.0.180 installed, have run it, and it reported no driver updates for your printer? If true, then there may be no resolution to your printing issues.
Are you running the released Mojave 10.14.4?