Sample JSON Payload to add a contact and add it to a list in API tester

I am using v2 API tester to add a contact and add it to a list. However, I cannot get the JSON payload correct. I can get a contact so I know I have a valid connection.

Can you check the payload below and tell me what the simple answer is?

error

[{
    "error_key": "json.field.invalid",
    "error_message": "#/import_data: Property was found but is not permitted at this location."
}, {
    "error_key": "json.field.missing",
    "error_message": "#/email_addresses: Property is required but not found."
}]

simplest payload I tried

{"import_data":[{
"email_addresses":["[email protected]"],
"first_name":"test",
"last_name":"User"}]

}