Screen record on macbook air 2020

i’m using macbook air 2020 right now, so i have a project to do but i need to screen record with audio. When i do the screen record with Quick time player, it didn’t show the option for the built in speaker so i can record the audio, it only has the macbook air mic which is if i using macbook air mic as an option for record the audio on macbook, it will record other sounds from outside too. Does anyone can help me how to find and fix it please i only need the computer audio built in speaker, but it doesn’t show any in the options of screen record for quicktime player