pf2e.fyi
From Pathfinder Dark Archive (Remastered), which isn't enabled.

Advanced Thaumaturgy

FEAT 6
ARCHETYPE
Archetype Thaumaturge
Prerequisites Basic Thaumaturgy

You gain one thaumaturge feat. For the purpose of meeting its prerequisites, your thaumaturge 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 thaumaturge feat.
Pathfinder Dark Archive (Remastered)ORC