help with logic pro on an old Macbook air

Hi I have a macbook air from 2017 and I want to buy Logic Pro but my computer is only updated to 10.14.6 and Logic requires 12.3 how can i update my mac to 12.3 i understand as well that there is the new macOS Monetary but that update but it isn't compatible with my type of computer. I hope theres a way to fix this problem because I really don't have the money for a new computer and logic pro.