Prevent duplicate entries to be created in MongoDB query

const ArtistSchema = new mongoose.Schema({
    firstname: {
        type: String,
        required: true,
        maxlength: [30, 'Max allowed 30 chars'],
    },
    lastname: {
        type: String,
        maxlength: [30, 'Max allowed 30 chars'],
        default: '',
    },
    url: {
        type: String,
        default:
            'https://cdn.vectorstock.com/i/preview-1x/48/06/image-preview-icon-picture-placeholder-vector-31284806.jpg',
    },
});

const postOneArtist = async (req, res) => {
    try {
        const artist = await Artists.create(req.body);
        res.status(201).json({ msg: 'Artist Added succesfully', artist });
    } catch (error) {
        console.log(error);
        res.status(500).json({ err: error.name, msg: error.message });
    }
};