Utilizing json if/then to require a parameter if not specified?

Question

So, I've got a json that has a handful of initial values, but as a user story I need to allow adjustments per point/object rather than at the top.

{"properties":{
  "p1":{},
  "p2":{},
  "pollInterval":{},
  "contents":{
    "anyOf":[{
      "properties":{
        ...
        },{

        ...
        }

    }]
  }
}

Here I want to require that if pollInterval is not in the initial properties, it has to be required in either of the anyOf properties blocks. I have the pollInterval definition of both anyOf blocks, though not they are not strictly required like some of the other data. I am just unsure of where to put it. Currently, I have it below the anyOf block as

if":{
        "not":{
            "properties":{
                "pollInterval":{}
            }
        }
    },
    "then":{
        "required":
        {
            
        }
    },

But it doesn't seem to force the pollInterval if I remove pollInterval from the top. How can I fix this?