You need to recruit Sorine Jurard and ask her to teach ytou how to make a steel crossbow in order to learn how to craft Steel Bolts.
If you want to get SOMEWHAT around it, however, the Rare Curios items from the Bethesda Creation Club shop include craftable Iron bolts (No perk requirements), Bonemold Bolts (Requires Steel smithing), Corkbulb bolts (No perk required), Orcish Bolt (Requires Orcish smithing), and Silver Bolts (No perk requirement).
You need to recruit Sorine Jurard and ask her to teach ytou how to make a steel crossbow in order to learn how to craft Steel Bolts.
If you want to get SOMEWHAT around it, however, the Rare Curios items from the Bethesda Creation Club shop include craftable Iron bolts (No perk requirements), Bonemold Bolts (Requires Steel smithing), Corkbulb bolts (No perk required), Orcish Bolt (Requires Orcish smithing), and Silver Bolts (No perk requirement).