Can't execute the UpdateOperation on cart.

[Wakil_eFoli]

I was trying to update the price of a cartline using the UpdateOperation.
To do that I've created the app and the extension and deployed the app. App when I check the output(STDOUT) I see the result as expected but meanwhile I'm getting an error:

Input:

Error

[
  {
    "path": [
      "operations",
      0,
      "update",
      "price"
    ],
    "explanation": "Field is not defined on UpdateOperation"
  }
]

Can someone point out where the problem is? Thanks!  

[Wakil_eFoli · Accepted solution]

Its working after I've added the the following to shopify.extension.toml file

api_version = "unstable"