m15 R3, cannot access one time boot menu

Hello there! I am currently trying to install Linux Manjaro. I have installed the iso file onto a USB. For some reason I am unable to boot Linux as I cannot currently find a way to see the Boot menu?

When I try to push F12 on startup, it brings up the BIOS, where there is a boot section, but in that boot section, there is no USB option. When I try to push F2 (which is the key said by the Alienware m15 manual to open the boot menu) it brings up BIOS settings. Does anyone know a way for me to access the boot menu so that I can boot into Linux?

Thanks in advance!