How to make a crafting recipe for a custom spawn egg in minecraft bedrock edition

This is not possible on vanilla Minecraft Bedrock. Use a behaviour pack, or a plugin if you’re on a PocketMine-MP Server.

You can make Shaped and Shapeless recipes:

In your addon's behavior folder, create another folder called "recipes". There you can add all your item's recipes in .json files (ex: spawn_egg.json). You can put one of the following codes in the file, editing it for your item:

1. Shaped recipe means the player has to put the ingredients in a certain pattern to produce the result: (example using the recipe for an acacia boat)

     { 
       "format_version": "1.12", 
       "minecraft:recipe_shaped": {
           "description": {  
               "identifier": "minecraft:acacia_boat" 
           }, 
           "tags": [
               "crafting_table" 
           ], 
           "groups": [ 
               "planks" 
           ], 
           "pattern": [
                    "#P#",
                    "###"
           ],   
           "key": {         
               "P": {           
                   "item": "minecraft:wooden_shovel"        
               },       
               "#": {           
                   "item": "minecraft:planks",          
                   "data": 4            
               }        
           },
           "result": {      
               "item": "minecraft:boat",        
               "data": 4        
           }    
       } 
     }

2. Shapeless recipe means that the player can put the ingredients in any order in the crafting table to produce the result. Just list the ingredients and how many ('count') of each ingredient. The ingredients can be any item in vanilla minecraft (ex: minecraft:apple) or any custom item that you make:

   {
      "format_version": "1.12",
      "minecraft:recipe_shapeless": {
          "description": {
              "identifier": "yourname:youritem"
          },
          "priority": 0,
          "ingredients": [
              {
                  "item": "name:firstingredient",
                  "data": 0,
                  "count": 2
              },
              {
                  "item": "name:secondingredient",
                  "data": 0,
                  "count": 1
              }

          ],
          "result": {
              "item": "yourname:youritem",
              "data": 0
          }
        }
    }

Note: You have to have "Experimental Gameplay" (in your minecraft world's settings) set to "ON" for your addon to work.

I got the code from guide.bedrock.dev.