Issue with adding comment

Hi there, I am making a node API. I am stuck at adding a comment to a story.

I am able to create a comment but instead of pushing it to a given story, it was trying to create a new instance of story.

Story.findOne(req.params.id, (err, foundstory) => {
        if(err){
            res.status(500).json({msg:err})
        }else{
            let comment = new Comment()
            comment.body = req.body.body
            comment.author = req.body.author

comment.save((err, comment) => {
                if(err){
                    res.status(500).json({msg:err})
                }else{
                    //pushing comment to comments array (ref) in story
                    foundstory.comments.push(comment)
                    foundstory.save()
                    res.status(200).json({msg:"Comment saved"})
                }
            })