Why does Lamine Yamal wear flags of 2 different countries on boots despite playing for Spain?

Spain forward Lamine Yamal wears flags of two different countries on his boots despite representing Spain. The flags are of Morocco and Equatorial Guinea, honouring his family heritage. His father has Moroccan roots and his mother was born in Equatorial Guinea. Notably, he was approached by Morocco to play for them but he told them "he feels Spanish".