Map function to build an array from filtered object

Question

I'm trying to get my head around map functions currently without much success.

I currently have a list of objects and am trying to remap to a new object using the map function to return a map indexed by the created property with a list of wooids.

Having written my map function, I only seem to be returning the last time.

const variants = [
{
   created: '2022-03-06',
    hashname: 'c78ba80402290724609a5e98c369c90984494152',
    hashobject: '80864e6329d5e305a512ace872ad7d56a3f41095',
    hashparent: '19c5d50ddddeb7c9a92469df78c47d9d611f1599',
    action: 'added',
    wooid: 7288
  },
{
   created: '2022-03-06',
    hashname: 'c78ba80402290724609a5e98c369c90984494152',
    hashobject: '80864e6329d5e305a512ace872ad7d56a3f41095',
    hashparent: '19c5d50ddddeb7c9a92469df78c47d9d611f1599',
    action: 'added',
    wooid: 7289
  }   
]

const res = Object.fromEntries(variants.map(k => [k.created, [k.wooid]]))
console.log(res)

Current output

{ '2022-03-06': [ 7289 ] }

Desired output:

{ '2022-03-06': [ 7289, 7288 ] }

Any help would be greatly appreciated as I'm unsure how to dynamically populate the array to include all other entires (6 in total).