A quick run through to get started.

1. Open the plugin

Open the plugin by clicking on the insert slot, select the submenu multi-channel plug-in, and the select BeatRig and then click LevelNorm2.

Depending on your settings ProTools can also sort the plugins by category, in that case you can fin the plugin in the section Dynamics.

Load LevelNorm2 on the last possible insert of your DAWs masterbus.
LevelNorm2 needs to read and analyse all final audio that will be exported. This is why it needs to be inserted on the last possible insert of your masterbus. And you need to play all the final audio of your DAW project at least once.

2. Play your final mix

Play all your final audio of your DAW project at least once. LevelNorm2 remembers your timeline. This means you are free to play your timeline in pieces in any order. This also means that when you change a small part in your timeline, you will only have to play that new part to let LevelNorm2 update the analysis for the whole track.

In the interface you can check the span of timeline range that is measured. By the start and end times at the top left and right. If there is a gap (a missing part of the timeline) it will be displayed in red in the middle of the start and end times.

3. Export your mix

Set your master fader at 0 dB and you are ready to export your audio.
The master fader sits behind LevelNorm in the process chain. This is why it needs to be set to 0 dB, so it does not change the loudness of the exported audio.

When you save your project (which a DAW does while exporting your audio), LevelNorm will adjust the volume of the audio that runs through it to match your target. You can also do this manually (but do not have to) when you stop playback and click on the red X icon in the LevelNorm2 interface. The X mark will then change into a green checkmark and the adjust gain value will be changed accordingly.

Thats how easy it is. In theory you will never have to open the LevelNorm2 interface to export to target.