`client.search()` vague suggest documentation

In the client.search() documentation, when I attempt to use the parameters suggestionField and suggestionText, I get error messages that indicate that my input string is null. However, I thought that suggestionText was supposed to be the key to my input string? Trying to get suggestions based on a user’s query isn’t clearly defined anywhere in the documentation or examples.

{
        index: 'random_index',
        suggestField: 'suggest',
        suggestText: 'query'
}

Error:

UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 1): Error: [null_pointer_exception] Input string is null

[Drewclam]

@rosman21’s solution works for me after changing prefix to text.

[flyinghawker]

Complement suggest is different scenarios from normal suggesters. Here I try in another way which may not work as expected but at least produce certain reasonable result. `{

  index: 'title',
  size:1, 
  from:0,
  body: {
    "query" : {
      "match": {
        "title": 'dolo'
      }
    },
    "suggest" : {
      "my-suggestion" : {
        "text" : 'dolo',
        "term" : {
          "field" : "title"
        }
      }
    }
  }
}

`