const userMessage Reaction = new UserMessage Reaction({ _id: mongoose.Types.ObjectId(), userId: "USERID", userName: "TESTUSERNAME", messageId: "TESTMESSAGEID", time: "TESTTIME" });

JavaScript
 const userMessageReaction = new UserMessageReaction({
        _id: mongoose.Types.ObjectId(),
        userId: "TESTID",
        userName: "TESTUSERNAME",
        messageId: "TESTMESSAGEID",
        time: "TESTTIME"
    });
Source

Also in JavaScript: