Using Here Technologies' REST-API with String adresses

I need to optimize a List of Adresses from my Database using Here Technologies.

The JSON data I am working with looks like this: Replaced some names and IDs to ensure the Data savety of my client.

"kunde": [
    {
    "kundenId": ///,
    "kundenbezeichnung": "Anger Ernestine",
    "kundenNr": "K-///",
    "tourHinweis": "",
    "nachname": "Anger",
    "vorname": "Ernestine",
    "strasse": "Bergstraße 18",
    "plz": "12169",
    "ort": "Berlin",
    "telefon1": "030 10449",
    "telefon2": "",
    "hatLieferAdresse": false,
    "schluesselVorhanden": false,
    "schluesselInfo": "",
    "zahlungsart": "Überweisung",
    "bruttoSumme": 1.0000,
    "menge": 1,
    "tourPos": 0,
    "positionen": [
        {
            "kundenId": ///,
            "belposId": ///,
            "artikelId": ///,
            "menge": 1,
            "artikelbezeichnung": "Champigongsauce mit Serviettenknödel",
            "artikelNr": "2302457",
            "warengruppe": "Diät",
            "bestellTypInfo": "Spalte 3",
            "bruttopreis": 1.0000
    }]},],
´´´
As already mentioned, I need to sort these Adresses to get the optimzed Route. Since my Client has more than 50 Customers per Tour, I cant use the Google Routing API, thats why I am using Here Technologies. The API works perfectly fine, but I don't have the GPS Koordinates stored in the Database. How can I use Here with normal String Adresses? 

You can make use of our geocode APIs. In the geocode API you can pass the String address to get the Coordinates. And once you have the Coordinates you can pass in the routing APIs to calculate the route.

Sample HERE geocode endpoint to get the Coordinates of string address.

https://geocode.search.hereapi.com/v1/geocode?q=jammu&apikey=your_api_key

More details of our geocode product are covered in below product document.

https://developer.here.com/documentation/geocoding-search-api/dev_guide/index.html