This quest will actually span almost all areas of the game, but it begins here. Begin by following the marker toward the southwest corner of the map.
As you arrive, you'll discover the Amun Stone Circle.
This launches a flash back, then the quest proper. Activate the stone circle to get a constellation matching game. For this first constellation, you do not need to rotate it at all- just move it slightly leftward and down.
Making the match reveals the constellation Amun, and completes this location, though the Bayek's Promise quest goes on.
When you have visited every stone circle, return to this very first one, back in Siwa.
Riding in, note a bit of silica roughly east of the circle, if you haven't already snagged it.
Approach the objective marker, rather than the stone circle itself, to make peace with this place.
This scene completes the quest. You also have gained the Stargazer achievement, and can now access the secret room beneath the Sphinx.
