UriFormatException: Invalid URI: Invalid port number for VirtualBox server using IPv6 Address

I've set up a server using a VirtualBox and determined that the address of that server is using IPv6. The address itself is http://[fe80::a00:27ff:fefe:70c5] and I can type that into a browser just fine and see my page. I've tried both of the following codes separately and received the same error both time:

 WWW www = new WWW(specURL +
             "api/v1/users/1/" + dest + "?access_token=" +
             accTok);
         yield return www;

 UnityWebRequest www = UnityWebRequest.Get(specURL +
             "api/v1/users/1/" + dest + "?access_token=" +
             accTok);
         yield return www.SendWebRequest();
 
         classList.text = www.downloadHandler.text;

where specURL is exactly http://[fe80::a00:27ff:fefe:70c5] and dest and accTok are things specific to the API of the server and shouldn't matter. I've also tried inputting http://[fe80::a00:27ff:fefe:70c5]:80 but that also returns the same error. The full error is this:

 UriFormatException: Invalid URI: Invalid port number
 System.Uri.Parse (UriKind kind, System.String uriString)
 System.Uri.ParseUri (UriKind kind)
 System.Uri..ctor (System.String uriString, Boolean dontEscape)
 System.Uri..ctor (System.String uriString)
 UnityEngineInternal.WebRequestUtils.MakeInitialUrl (System.String targetUrl, System.String localUrl) (at C:/buildslave/unity/build/Modules/UnityWebRequest/Public/WebRequestUtils.cs:527)
 UnityEngine.MonoBehaviour:StartCoroutine(IEnumerator)
 CanvasHttpsRequest:LookForClasses() (at Assets/CanvasHttpsRequest.cs:72)
 UnityEngine.EventSystems.EventSystem:Update()

My assumption is that the formatting of my URI is incorrect, especially in regards to IPv6. Is there anything I'm missing?