Vega Lite dynamically set scale.domain

[davecook88]

I'm struggling to work out how to dynamically set the domain of my chart. Ideally I'd be able to do something like:
https://stackoverflow.com/questions/66170320/dynamic-scale-domain-in-vega-lite

{
  "scale": {
    "domain": [rangeMin * 0.8, rangeMax * 1.1]
  }
}

I've found this question on StackOverflow and I hit exactly the same problem. When I try to use `expr`, I get the error "Incorrect type. Expected "null". What version of Vega Lite does this integration use and is there a link to the documentation for this version?