Your info about Visa to Cambodia will be checked and verified on arrival at the Immigration Online System. Once you arrive you need to go to the e-Visa Immigrations Counter Checkpoint. Remember that you need to give a copy of your eVisa to the Immigrations Officer!
Look for the e-Visa signboard and follow instructions.
Siem Reap Airport
Please go to any counter from 02 - 08
Phnom Penh Airport
Go to any counter from 03 - 09