Mono audio to two track mono

How do I record a single mono audio XLR input to two (2) track mono?
ATEM Television Studio Pro HD and Hyperdeck Studio Mini

If you use an XLR Y-splitter cable, you should be able to feed the single audio signal into both of the XLR inputs on the ATEM.

The HyperDeck Studio Mini has a setting to control how many channels to record, so you could set it to record 2-channel audio (how many channels to record is pretty much the only audio option on the HyperDeck Mini).

The best way is to get a small 2-channel mixer like the Sound Devices MixPre and “pan” the single input to both channels, and connect it to the Stuido Mini audio inputs. The Pan control will split the single input to the mixers two outputs. Be sure,to set the mixer outputmto “Line” level.
Cheers