To add a new calendar to your account, you can visit https://my.x.ai/connect. Select Google, Office 365, or Outlook.com and follow the authorization steps, which are the same as when you first signed up for x.ai.
When you add multiple calendars, like your work and personal calendars, x.ai is able to consider your availability across those calendars.
You can view your Connected Calendars in your Account settings.
Once you have multiple calendars connected, you will also have the option for how you want x.ai to pick which calendar to add events to.
By default, x.ai will dynamically add events into the calendar that best matches the email address you used to start the meeting. If you'd prefer that all meetings are added onto a single calendar, you can also select that.
You can select this in your Default Calendar Preferences for Ad hoc meetings, customize it on a Meeting Template (so different types of meetings can have different preferences, and even do it for one-off meetings from the Meeting Creator.