l.Name.toLocaleLowerCase

[ChinmayDeyUI]

After I added your package in my project I got below error.
TypeError: undefined is not an object (evaluating 'l.Name.toLocaleLowerCase')

When I used your top20.json it works, but if I used my own json I got above error.
Your json is like
[{"Name": "Åland Islands","Value": "Åland Islands","Code": "AX","Id": 1 }]
and my json is like
[{"id":1,"city":"Kolkata","type":"Metro","city_class":"A","state":"West Bengal","state_id":2,"type_id":"M"}]

[Twelvefat]

you must include Name key to your Json. sorry for my bad english

it look like :
[{"Id":1,"Name":"Whatever"}]

[nericode]

@ChinmayDeyUI You json is incorrect please use map function to convert json:

 var data = json.map((item) => {
    // item values can change, but no Id, Name, Value
     return {
        Id: item.Id,
        Name: item.city,
        Value: item.type,
     };
});