bug fix + use id instead of username for lookup

pages/api/avatar/[id].ts

@@ -8,10 +8,10 @@ export default async function Index(req: NextApiRequest, res: NextApiResponse) {
   const session = await getServerSession(req, res, authOptions);
 
   const userId = session?.user.id;
-  const userName = session?.user.username?.toLowerCase();
+  const username = session?.user.username?.toLowerCase();
   const queryId = Number(req.query.id);
 
-  if (!userId || !userName)
+  if (!userId || !username)
     return res
       .setHeader("Content-Type", "text/plain")
       .status(401)
@@ -37,7 +37,7 @@ export default async function Index(req: NextApiRequest, res: NextApiResponse) {
 
     if (
       targetUser?.isPrivate &&
-      !targetUser.whitelistedUsers.includes(userName)
+      !targetUser.whitelistedUsers.includes(username)
     ) {
       return res
         .setHeader("Content-Type", "text/plain")