Open your crafting menu (2×2 or 3×3 grid depending on version)
Place 7 cobblestone in the crafting grid to form the dispenser base (all slots except the center)
Place 1 redstone dust in the center slot
Place 1 bow in the slot directly above the center
Place 1 dropper? (If needed for your version) in the slot directly below the center
Take the crafted dispenser from the output slot
If crafting is not available in your version, use the dispenser recipe instead: cobblestone around the edges with redstone in the center (7 cobblestone + redstone)