Use the Hub shop marked with a bottle
Alchemist's Apprentice requires fifteen consumable purchases in the Hub. Look for the bottle-marked shop. Buying weapons or armor in the Arsenal is not the consumable purchase the achievement asks for, and finding a potion during a run is a different action.
Verify one purchase before spending more
- Check the achievement's present progress, if the platform shows a counter.
- Open the bottle-marked consumable shop in the Hub.
- Purchase a consumable option you can afford.
- Check progress again before continuing toward the fifteen-purchase goal.
Do not diagnose the counter from the wrong shop
A counter that does not match your remembered weapon purchases does not establish a bug. First verify that the transaction was a Hub consumable purchase. Do not discard equipment, consume potions in combat, or restart a run to imitate that transaction.