I guess you cannot until Microsoft adds Visio 2019 to Microsoft HUP licensing model.
But clearly Visio is more a "professional" software than a "Home user" program.
So I doubt they would do that.
HOWEVER try to use/purchase "My.VisualStudio" program (ex MSDN).
I know they offer Visio 2019 for testing/evaluation purpose with a "MSDN-like" license.