In Debian Sid, i wasn't able to use my builtin microphone in Thinkpad T14 because the required kernel modules weren't activated.
These Kernel modules must be active:
CONFIG_SND_SOC_AMD_RENOIR=m
CONFIG_SND_SOC_AMD_RENOIR_MACH=m
So I had to compile the kernel for it to work.
I recommend setting this up so other users won't have the same problem.