improvement for the backend api

components/layout/app-sidebar.tsx

@@ -143,13 +143,13 @@ export function AppSidebar({ ...props }: React.ComponentProps<typeof Sidebar>) {
         {user && (
           <NavUser
             user={{
-              name: `${user.first_name}${
-                user.last_name ? " " + user.last_name : ""
-              }`,
+              name: user.username || `User ${user.telegram_id}`,
               email: user.username
                 ? `@${user.username}`
                 : `ID: ${user.telegram_id}`,
-              avatar: `https://ui-avatars.com/api/?name=${user.first_name}`,
+              avatar: user.username
+                ? `https://ui-avatars.com/api/?name=${user.username}`
+                : `https://ui-avatars.com/api/?name=User`,
             }}
           />
         )}