there is an array cateogoryList in the defined Schema:

const mongoose = require("mongoose");
const Schema = mongoose.Schema;

const ProductCateogorySchema = new Schema({
      user:{
            type:Schema.Types.ObjectId,
            ref:"users"
      },
      cateogoryList:[
            {
                  cateogoryName:{
                        type:String,
                        required:true
                  },
                  cateogoryDes:{
                        type:String
                  }
            },
            {
                  cateogorySubList:[
                  
                  ]
            }
      ],
      date:{
            type:Date,
            default:Date.now
      }
});

module.exports = mongoose.model("cateogories",ProductCateogorySchema);

now add data to this array through the form. Normally, you have to query the Schema first, find the cateogoryList, then add the data, and then save it. But I encounter this problem here:
cannot manipulate the cateogoryList array queried into the Schema, or maybe I don"t know how to operate it, and then I can"t write the data.
on the front is the method of this POST:

router.post("/cateogory/add",urlencodedParser,(req,res) => {
      CateogoryOneSchema.find().then(cateogory => {
            if(!cateogory){
                  console.log("cateogory    :"  + cateogory)
                  const newFields = {
                        cateogoryName: req.body.cateogoryOneName,
                        cateogoryDes:req.body.cateogoryOneDes
                  }

                  const category = {};
                  category.categoryList = [];
                  category.categoryList.push(newFields);
                  cateogory.save();
            }
      })
})

the cateogory printed to is empty data that has just been inserted unsuccessfully:

but when I use category.categoryList, I will report an error that I can"t use push. What should I do?
Thank you very much!