convert simple curl data request to powershell invoke-webrequest - json

Question

Converting a very simple Plaid API curl data request to a powershell invoke-webrequest
what works:
curl -X POST https://tartan.plaid.com/balance \
-d client_id=client-id-value \
-d secret=secret-value \
-d access_token=access-token-value
What I'm trying unsuccessfully in Powershell
#test powershell api call
$hash = #{ client_id = "client-id-value";
secret = "secret-value"
access_token = "access-token-value"
}
$JSON = $hash | convertto-json
#Invoke-WebRequest -uri "https://tartan.plaid.com/balance" -Method POST -Body $JSON
This returns a plaid error 1100 (client id missing), so I know some API functionality is working, but it's not parsing input data correctly.
My biggest misunderstanding is how to translate a "curl -data" value into the proper Powershell parameter.
Is this a header value, body value? etc.

Answer 1

Unless the target url expects the POST body to be in JSON format, skip the ConvertTo-JSON step completely.
When the chosen HTTP method is POST, Invoke-WebRequest will automatically take all the keys in the hashtable supplied to the -Body parameter and construct a body payload similar to that of curl -d:
$POSTParams = #{
client_id = "client-id-value"
secret = "secret-value"
access_token = "access-token-value"
}
Invoke-WebRequest -Uri "https://tartan.plaid.com/balance" -Method POST -Body $POSTParams