Greetings to everyone I'm new in NodeJS and I got this error "Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client" and I know on which line of code that error appears but I don't know how to fix it. Can anyone help me here is the code

router.get("(.*)", async (ctx) => {
        try {
          const shop = ctx.query.shop;
          let user = await Shopify_custom_session_storage.findAll({
              raw: true,
              where:{
                shop: shop
              },
              limit:1
            });

          //This shop hasn't been seen yet, go through OAuth to create a sessrsion
          if (user.length == 0 || user[0].shop == undefined) {
            ctx.redirect(`/auth?shop=${shop}`);
          }else{
            await handleRequest(ctx);
            ctx.session.userData = { // Problem appears here
              shop: user[0].shop,
              accessToken: user[0].accessToken
            }; 
          }
          
          // if (ACTIVE_SHOPIFY_SHOPS[shop] == undefined) {
          //   ctx.redirect(`/auth?shop=${shop}`);
          // } else {
          //   await handleRequest(ctx);
          // }
        } catch(err) {
          console.log(err);
          throw err;
        }
      });