Hey Filipino here - i honestly don’t know the answer (or maybe I’m too old to remember my history class) but as per Wikipedia
The name Filipino, as a demonym, was derived from the term las Islas Filipinas ‘the Philippine Islands’, the name given to the archipelago in 1543 by the Spanish explorer and Dominican priest Ruy López de Villalobos, in honor of Philip II of Spain.
Hey Filipino here - i honestly don’t know the answer (or maybe I’m too old to remember my history class) but as per Wikipedia
https://en.wikipedia.org/wiki/Filipinos