Find Ancient Debris in the Nether
Mine Ancient Debris with a Diamond or Netherite Pickaxe
Smelt Ancient Debris in a Furnace or Blast Furnace to get Netherite Scrap
Collect Gold Ingots
Combine 4 Netherite Scrap and 4 Gold Ingots in a Crafting Table to make 1 Netherite Ingot