Could someone share a working startorderstrategy json body?

Does anyone have a working startorderstrategy json example they can share? Minus accountId.
I pulled the below json body directly from Tradovate using the network monitor. Using Insomnia I set up a post using the json but got a 404 response…

details of post-
url: https://demo.tradovateapi.com/v1/orderStrategy/startorderstrategy

header:
accept:application/json
authorization: bearer xxxx
content-type: application/json

body:

{"accountId":111222,"symbol":"MESZ1","orderStrategyTypeId":2,"action":"Sell","params":"{\"entryVersion\":{\"orderId\":0,\"orderQty\":1,\"orderType\":\"Limit\",\"price\":4531.75,\"timeInForce\":\"GTC\"},\"brackets\":[{\"qty\":1,\"profitTarget\":-1.5,\"stopLoss\":1,\"trailingStop\":true}]}"} 

I have successfully executed placeOrder and placeOCO.
startOrderStrategy has me stumped.

Edit 1: There appears to be something incorrect with Params parser. If I change orderStrategyTypeId: 0 . the response becomes 400 - order strategy typeid should be greater than 0. That tells me the endpoint receives the request and processes the top level of the json. The second level, Params, is failing with an error that not being sent back rather a generic 404.