This command will make you be able to make custom crafts in vanilla Minecraft, (you will be crafting in a dispenser)
Replace the coords by the coords of your dispenser and the slots by your crafting recipe.
!! There are two commands here, one in a repeating command block always active and one in a chain, Conditional and always active on top of the other.
The second command block will determinate the crafted block at the end
In the command, you will see [{slot:0b,id:"Enter block"}]
You NEED to put minecraft: before entering your block, otherwise, it won't work
Make sure to make the difference between the two commands !