Hi Nhan,
MDM-AP DAP control and status registers are accessible via the Debug Access Port using SWD. The MDM-AP available registers are shown in table 12-5 from Reference Manual.
User can access MDM-AP registers using link server from MCUXpresso. There are some scripts that you can use as reference to see how to read MDM-AP regs. Refer to "Chapter 10.4 - LinkServer Debug Operation" from MCUXpresso User Guide to run link scripts from MCUXpresso and What commands are supported in Redlink Server? to get a better understanding of linkserver commands.
See below output from K32L3Aconnect.scp script on MCUXpresso.

User can also read access MDM-AP registers using J-Link Commander with a J-Link probe. See below example using J-Link Commander:

Regards,
Jing