pf2e.fyi
From Pathfinder Impossible Magic, which isn't enabled.

Advanced Rune Magic

FEAT 6
ARCHETYPE
Archetype Runesmith
Prerequisites Basic Rune Magic

You gain a runesmith feat. For the purpose of meeting its prerequisites, your runesmith level is equal to half your character level.

Special You can select this feat more than once. Each time you select it, you gain another runesmith feat.
Pathfinder Impossible MagicORC