correct way to handle errors run time errors - tRPC

I want to handle errors, for example when executing this mutation an error appears ```tsx "use client"; etc const mutationAdd = trpc.user.addUser.useMutation({ onSuccess: async (data) => { await utils.user.getUsers.refetch(); router.push("/admin/all-employees"); }, onError: (error) => { toast({ variant: "destructive", action: <ToastAction altText="Try again">{error.message}</ToastAction>, }); return; }, }); ``` server router ```tsx addUser: publicProcedure .input( z.object({ username: z.string(), name: z.string(), email: z.string().email(), password: z .string() .min(5, "password should be at least 5 digits long."), role: z.string(), }) ) .mutation(async ({ input }) => { const newUser = await auth.api.createUser({ headers: await headers(), body: { name: input.name, email: input.email, password: input.password, role: input.role, data: { username: input.username, }, }, }); return newUser; }), ```