You can do your own interval training when the effort guide feature is unlocked after a couple hours of running with Vi. This feature will help to tell you whether your pace is good for intervals but it is not designated interval training. Meaning, Vi will not guide you when you should stop running at that pace or your interval should be finished), will not tell you how many intervals to do, advise on the timing between intervals, etc.
You can also turn off auto-pause in the settings and do intervals before then, but Vi will pick that up as an inconsistent pace.
We will add full interval training around the time training plans are released. We will share a timeline for this release soon.