Dual Boot Issue Windows 8 & Ubuntu

I’m on holiday vacation and installed Ubuntu 20.04 in a dual boot config with Windows 8 on an HP Envy 23 (all-in-one) for a friend who was tired of the slow performance of Windows.
The installation went fine but now I don’t see an option in the Boot Menu for Linux/Ubuntu, only the Windows Boot Manager, USB and Network Controller. Also, no GRUB menu appears upon bootup, instead it boots directly to Windows. I read somewhere that I may have installed incorrectly in a legacy boot configuration instead of UEFI but not sure if that is correct or how I can fix it. So currently, I can’t figure out how to boot into Ubuntu without going from the ISO on the usb rather than the fresh install on the HDD. Thanks for any help you can provide!

So I figured out the issue. When I created the usb Ubuntu ISO image with Rufus, I should have selected the GPT option instead of MBR so that it allowed the UEFI boot. Reinstalled Ubuntu over the previous installation and all good now!