@MosesTech
With the older slow PCs, this was easy because there was a lot of time to press the keys needed to interrupt the boot process. But the newer PCs are so fast, this has become a very difficult thing to do.
When you reboot, press the Esc key repeatedly and rapidly -- as soon as the PC turns on. If you wait, even for a second, that will be to late to interrupt the boot process.
When the HP Startup Menu then shows up, you should be able to press the key indicated to get into the BIOS/UEFI options.
I am a volunteer and I do not work for, nor represent, HP