How can I disable IO?

Hi, How can I disable IO? I mean how can I change my code FMU only.
I fixed PARAM_DEFINE_INT32(SYS_USE_IO, 1); to PARAM_DEFINE_INT32(SYS_USE_IO, 0); in src/drivers/px4io/px4io_params.c
After I change this, I use make px4_fmu-v5_default to build.
Then, I could find the value regarded to SYS_USE_IO in /src/build changed to 0.
However, instead of change the value, I got below result on my terminal during build using make px4_fmu-v5_default.
Is my way of changing SYS_USE_IO correct?

Your method should work, but a simpler solution is just updating SYS_USE_IO to 0 in QGroundControl or nsh.

Also, you can refer to this document: