fix(dashboard): Fix api 'auto' options (#3807)

packages/dashboard/src/lib/graphql/api.ts

@@ -4,8 +4,8 @@ import { DocumentNode, print } from 'graphql';
 import { uiConfig } from 'virtual:vendure-ui-config';
 
 const API_URL =
-    uiConfig.api.host +
-    (uiConfig.api.port !== 'auto' ? `:${uiConfig.api.port}` : '') +
+    (uiConfig.api.host !== "auto" ? uiConfig.api.host : `${window.location.protocol}//${window.location.hostname}`) +
+    `:${(uiConfig.api.port !== 'auto' ? uiConfig.api.port : window.location.port)}` +
     `/${uiConfig.api.adminApiPath}`;
 
 export const SELECTED_CHANNEL_TOKEN_KEY = 'vendure-selected-channel-token';