Create an external check keyname “echo.json.lld[]” 

#!/bin/bash
echo '[
  {
    "id": "2756893",
    "name": "M",
    "quantity": "49"
  },
  {
    "id": "2756892",
    "name": "L",
    "quantity": "105"
  },
  {
    "id": "2756895",
    "name": "XL",
    "quantity": "83"
  }
]'

Create discovery rule LLD macros

nameJSONPath
{#ID}$.id
{#NAME}$.name

https://www.reddit.com/r/zabbix/comments/k0pzyi/tutorial_for_lld_dependent_items_from_the_same/