In the past when I've had to parse JSON, or construct a schema, and I need to allow for "null", this has always worked for me in Power Automate:
{
"type": "object",
"properties": {
"accountId": {
"type": "string"
},
"industryTags": {
"type": [
"string",
"null"
]
}
}
}
This is also confirmed here: https://stackoverflow.com/a/56708378/3123109.
Now I'm trying to work on a child flow and need it to receive null values and it isn't working. The field doesn't show up in the parent child request:

If I change it to "type": "string", then it does show up. But then inevitably some data is sent over without industryTags and it fails.
So how do I allow for null values in this use case?