Is there any chance that I can install the linux kernel 4.15 on zorin?
I have a PC that works only with that kernel...
I use zorin OS Lite 16
You could try the solution with 2 votes here but change the line that says 18.04 to 20.04 and change the kernel number to the one that comes with Lite. No guarantees.
Yes it's possible, but you must read about doing this here:
There is a link there where to get them + installation and use instructions with cautions.
You would use these at your risk. Kernel 4.15 is End of Life since 2018. No security updates since then.