Correcting data provider path

gui/rpk-gui/src/providers/data-provider.tsx

@@ -96,7 +96,7 @@ export const dataProvider: DataProvider = {
     };
   },
   create: async ({ resource, variables }) => {
-    const response = await fetch(`${API_URL}/${resource}`, {
+    const response = await fetch(`${API_URL}/${resource}/`, {
       method: "POST",
       body: JSON.stringify(variables),
       headers: {