How to append element into an object inside an array of objects in dynamodb with node.js

Question

This is my item in a dynamodb table. I am trying to append data into an object that is inside an array. i am pretty new dynamodb. I tried using KeyExpression but that seem to work with only key items.

{
 "category": "Causal Wear",
 "styles": [
  {
   "style_Id": "534f",
   "sizes": [
    "xl",
    "l",
    "xs"
   ],
   "colors": [
    "red",
    "green",
    "yellow"
   ]
  },
  {
   "style_Id": "3435",
   "sizes": [
    "xl",
    "l",
    "xs"
   ],
   "colors": [
    "red",
    "green",
    "yellow"
   ]
  },
  {
   "style_id": "crnd9201"
  }
 ]
}

and I want to append data into a object with style_id = "crnd9201"

This is my data

{
 "sizes":['xl'],
 "colors":['red','blue']
}

this is what i am trying to achive

{
     "category": "Causal Wear",
     "styles": [
      {
       "style_Id": "534f",
       "sizes": [
        "xl",
        "l",
        "xs"
       ],
       "colors": [
        "red",
        "green",
        "yellow"
       ]
      },
      {
       "style_Id": "3435",
       "sizes": [
        "xl",
        "l",
        "xs"
       ],
       "colors": [
        "red",
        "green",
        "yellow"
       ]
      },
      {
       "style_id": "crnd9201",
       "sizes":['xl'],
       "colors":['red','blue']
      }
     ]
    }