Best internal ZIGBEE RADIO MODULE

Just wanted to ask on the easiest internal ZIGBEE RADIO MODULES to install. Have looked at the RaspBee II Overview but seems too confusing to install.

Any suggestions please, need internal only.

Is internal a must?

I have never had a good experience with an Internal zigbee module. In fact most of the time I’m trying to get ti as Far away from interference sources as possible…

Yes would need it as internal, I can only see RaspBee II Overview as an option in the recommended modules for internal unless I have missed others.
Just wondering if anyone has simple guidelines for installing it. I have tried Conbee 2 stick and it was almost plug and play but wondered if the same for Raspbee.