Problem with remote dataset JSON

Indeed json in that format might not be correctly understood there.

You could have it as an array like here Remote Dataset - Trouble configuring Remote Data Path

so say something like this in json.

 {
         "wifi": "GuestAP",
         "rows":[
		{
            "tglAwal": "7 Mei 2018",
            "tglAkhir": "13 Mei 2018",
            "password": "WifiPass100"
		},
		{
			"tglAwal": "15 Mei 2018",
            "tglAkhir": "23 Mei 2018",
            "password": "WifiPass122"
		}
    ]
 }

3 columns with the remote data path corresponding to the names in .json ie
tglAwal, tglAkhir and password for your 3 columns.

data root in dataset would be rows as well as in the other example and the processed data should be

 "processed": [
      [
         {
            "tglAwal": "7 Mei 2018",
            "tglAkhir": "13 Mei 2018",
            "password": "WifiPass100"
         },
         {
            "tglAwal": "15 Mei 2018",
            "tglAkhir": "23 Mei 2018",
            "password": "WifiPass122"
         }
      ]
   ],