Have you read the full document on working with HDR in PrPro? It's not all that easy at the moment, especially as the internal monitors ... Source, Program, and Reference (including transmit out) are all locked to Rec.709. So even if your media and sequence are say Rec.2100/HLG, the monitors will be showing Rec.709 image.
Meaning you have to judge by having your scopes set to HDR and the proper colorspace ... not easy.
So for proper image evaluation, they state you must have one of several specific BlackMagic or AJA output boxes or cards to take the signal outta the computer away from the OS and feed a proper HDR signal to a fully HDR capable monitor.
The public beta version does seem to allow some use of the Transmit Out process to get at least a quasi-HDR image to a monitor if Windows is set right, the monitor is capable and etc etc etc.
Note, this is a 'test of working concept' in the public beta, not at all guarnteed to be accurate.
Plus ... it matters which option you take for your working sequence and export. As in using the whites at 203 option for the project settings. And you need to know the proper export settings. For that, you really need to study their list of proper settings, it's pretty detailed.