Node-Fetch - Danish Letters bad JSON response

I'm trying to make a few query's on a Real Estate Website.

When i make the fetch request with words like 'Næstved','Præstø',Karrebæksminde, i get a bad response because æ,ø etc gets replaced by ? symbol ??? I tried to escape the response and it seems to work at times ... but i mostly get empty responses....

You can try yourself to make a query here: https://home.dk/umbraco/backoffice/home-api/BoligOrAddress/Boligdata?max=100&searchstring=N%C3%A6stved

Here is the code:

var cities = [
  'København',
  'København K',
  'Næstved'
];

var promises = cities.map(city => 
fetch(`https://home.dk/umbraco/backoffice/home-api/BoligOrAddress/Boligdata?max=1000000000&searchstring=${city}`)
.then(response => response.json())
.then(validate => { if(validate.Successed && validate.Status === 'OK') return validate })
.then(pushAlll => { pushedSuggestions.push(pushAlll); return pushAlll })

Promise.all(promises).then(results => {
    console.log(results);
});

The problem is i get results like this { suggest: 'N�stved', count: ''} When i should be getting this:

[
    {
    suggest: "Næstved kommune",
    count: "854"
    },
    {
    suggest: "Næstved, 4700",
    count: "406"
    },
    [
    {
    suggest: "Næstved Landevej, 4243 Rude",
    count: "1"
    },
    {
    suggest: "Næstved Landevej, 4250 Fuglebjerg",
    count: "1"
    },
    {
    suggest: "Næstvedvej, 4100 Ringsted",
    count: "2"
    },
    {
    suggest: "Næstvedvej, 4230 Skælskør",
    count: "3"
    },
    {
    suggest: "Næstvedvej, 4684 Holmegaard",
    count: "2"
    },
    {
    suggest: "Næstvedvej, 4720 Præstø",
    count: "4"
    },
    {
    suggest: "Næstvedvej, 4750 Lundby",
    count: "1"
    },
    {
    suggest: "Næstvedvej, 4760 Vordingborg",
    count: "4"
    }
]

via Octavian L