Currently, the Primal spells that require a Will save are the following:
Tame, Charm, Fear, Lose the Path, Positive Attunement, Compel True Name, Banishment, Glimmer of Charm, Mariner's Curse, Ravening Maw, Blanket of Stars, Blinding Fury, Catch Your Name, and Burning Blossoms.
As of this answer, Archives of Nethys is not well suited for searching on the basis of spell saving throw type or tradition. Its search function looks at the name and text of a spell, but not its other characteristics. Furthermore, AoN's spell index is not otherwise filterable by saving throw type.
Instead, this list was gathered using PF2 Easy Tools, which provides slightly better spell filtering functionality than Archives of Nethys. I retrieved the list by:
- Filtering the total spell list by the Primal tradition (using the top menu options)
- Entering "Will" in the save type filter in the table generated below.