Using two IQ Panel2Plus (one as secondary)

Can I use two IQ Panel2Plus (QK9202-AK2C-840) in the same system? One for the side door and one for the front door?

Thanks

No. The IQ panel 2+ is the primary alarm panel and only one can be used per system/location.

A second IQ panel 2+ would be a separate Alarm.com account and location.

You would want the IQ Remote instead, which is a dedicated secondary touchscreen. The IQ panel 2+ supports partitions if you need to arm certain areas independent of others.