A problem when putting string variable into request URL

Hello how are you I am going to pass a variable into a URL. But "%E2%80%8B" is attached at the end of the variable.

This is my code.

 [System.Serializable]
     public class Param {
         public string key;
         public string value;
         public Param(string k, string v) {
             key = k;
             value = v;
         }
     }
 
     private string parseParam (List<Param> paramList) {
 
         string strParam = "?";
 
         foreach (Param param in paramList) {
             strParam += param.key;
             strParam += "=";
             strParam += param.value;
             strParam += "&";
         }
 
         return (strParam = strParam.Remove (strParam.Length - 1));
     }
 
 private IEnumerator searchCity() {
         string cityQuery = searchFilter.text;
         string url = "http://geodb-free-service.wirefreethought.com/v1/geo/cities";
         List<Param> paramList = new List<Param> ();
         paramList.Add (new Param ("namePrefix", cityQuery));
         paramList.Add (new Param ("limit", "10"));
         paramList.Add (new Param ("offset", "0"));
         paramList.Add (new Param ("hateoasMode", "false"));
         url += parseParam (paramList);
         UnityWebRequest req = UnityWebRequest.Get(url);
         req.SetRequestHeader ("Content-Type", "application/json;charset=UTF-8");
         yield return req.SendWebRequest ();
         Debug.Log (req.url);
         if (req.error != null) {
             Debug.Log ("Getting Location Data Failed");
         } else {
             Debug.Log (req.downloadHandler.text);
         }
 }

When I put this city name "Liverpool" instead of the variable "cityQuery", the right result shows and at this time, the URL becomes "http://geodb-free-service.wirefreethought.com/v1/geo/cities?namePrefix=Liverpool&limit=10&offset=0&hateoasMode=false" but when I put the variable "cityQuery" then the result becomes "http://geodb-free-service.wirefreethought.com/v1/geo/cities?namePrefix=Liverpool%E2%80%8B&limit=10&offset=0&hateoasMode=false" and so the result not showing.

Any help is appreciated. Please help me with this question. Thanks

Sprietsma