Quick web search led me to this which is an Acer owner trying to install PopOS. Likely similar steps that you will need to follow to be successful.
AHCI mode on Acer Predator Triton 300 PT315-52 Laptop

Hey all. Trying to switch over to Pop!_OS. Need my laptop, an Acer Predator Triton 300 (PT315-52) to be in AHCI mode to do this.

Acer Community