https://www.gamespot.com/articles/injustice-2-pc-release-date-announced-open-beta-no/1100-6454708/

Injustice 2 launched in May for Xbox One and PlayStation 4, but PC was left out. PC players won't have to wait much longer now, as the fighting game sequel will land on PC through Steam and the Windows 10 store on November 14.

You don't have to wait until then to play on PC, however, as Warner Bros. is holding an open beta on Steam right now. The online-only beta lets you play 1v1 matches. Warner Bros. is holding the beta for the purpose of testing the network code and infrastructure.