I am a Chinese Steam Vegas user, I accidentally discovered this software and purchased it. But the Steam version doesn't have central cloud and speech-to-text.
I think that your choices are to contact Steam about the issue; or
... purchase Vegas Pro directly from Vegas where those features are included via licensing arrangements.
@huachayu This is correct...Steam versions do not have any of the cloud based features. This is a limitation of the Steam licensing system and we are unable to provide these services on that platform.