Vegas Pro has always been able to create, edit, and import .srt and .txt Cosed Caption files and place them on the timeline in CEA-608 or CEA-708 formats. They can be burned in or exported.
What CC feature are you looking for? There is a great free AI speech-to-text program at Happy Otter Scripts called Batch Whisper AI.
The current version (released last month) is version 22. There is no "VEGAS Pro 23" at this time...
And, yes, it can. If you want the audio automatically changed to text, that would require the hub but if you manually enter the text or use some other method of transcribing, then the hub won't be needed.