The presser foot is located on the fabric pressure bar of the sewing machine and is involved in the feed mechanism during sewing.
Source:
Schlums, Ulla; Dressler, Heike; Decker, Sonja (2022), Fertigung Bekleidung, 1. Auflage, Haan-Gruiten: Verlag Europa-Lehrmittel, S. 22