ValidationFailed: user: Cast to ObjectId failed for value … (type Object) at path “user” because of “BSONError”

I am working in a NextJs project with mongoDB. When I am submitting a form its showing me this error…

events validation failed: user: Cast to ObjectId failed for value “{ success: true, data: { _id: ‘66d617672c64115d9df381f9’, firstName: ‘aaa aaa’, email: ‘aaaa@gmail.com’, isActive: true, isAdmin: true, clerkUserID: ‘user_2lWrZ1KjGMhfMiPsu9G8Qisn7jj’, createdAt: ‘2024-09-02T19:52:07.123Z’, updatedAt: ‘2024-09-02T19:52:07.123Z’, __v: 0 } }” (type Object) at path “user” because of “BSONError”

my event schema

import mongoose from "mongoose";

const eventSchema = new mongoose.Schema(
  {
    name: {
      type: String,
      required: true,
    },
    description: {
      type: String,
      required: true,
    },
    organizer: {
      type: String,
      required: true,
    },
    guests: {
      type: Array,
      required: true,
    },
    location: {
      type: String,
      required: true,
    },
    date: {
      type: String,
      required: true,
    },
    time: {
      type: String,
      required: true,
    },
    images: {
      type: Array,
      required: true,
    },
    ticketTypes: {
      type: Array,
      required: true,
    },

    user: {
      type: mongoose.Schema.Types.ObjectId,
      ref: "users",
      required: true,
    },
  },
  { timestamps: true }
);

// define the Event model with the schema
if (mongoose.models && mongoose.models.events) {
  delete mongoose.models.events;
}

const EventModel = mongoose.model("events", eventSchema);
export default EventModel;

this is user-schema

import mongoose from "mongoose";

const userSchema = new mongoose.Schema(
  {
    firstName: {
      type: String,
      required: true,
    },

    email: {
      type: String,
      required: true,
      unique: true,
    },
    isActive: {
      type: Boolean,
      default: true,
    },
    isAdmin: {
      type: Boolean,
      default: false,
    },
    clerkUserID: {
      type: String,
      required: true,
      unique: true,
    },
  },
  { timestamps: true }
);

// check if user model is already exists
if (mongoose.models && mongoose.models["users"]) {
  delete mongoose.models["users"];
}

const UserModel = mongoose.model("users", userSchema);
export default UserModel;

function i’m using

import { connectMongoDB } from "@/config/dbConfig";
import UserModel from "@/models/user-model";
import { auth } from "@clerk/nextjs/server";
import { NextRequest, NextResponse } from "next/server";

connectMongoDB();

export async function GET(request: NextRequest) {
  try {
    const { userId } = auth();
    if (!userId) throw new Error("Unauthorized request");

    const userInMongoDB = await UserModel.findOne({ clerkUserID: userId });
    return NextResponse.json({ user: userInMongoDB }, { status: 200 });
  } catch (error: any) {
    return NextResponse.json({ message: error.message }, { status: 500 });
  }
}

now let me know, how can I resolve this!!!