Ik ben blij met mijn cadeau. (I'm happy with my present.)
blij takes "met" (blij met = happy with). Example: Ik ben blij met mijn cadeau. (I'm happy with my present.)
Ik ben blij met mijn cadeau. — I'm happy with my present. The preposition met is fixed, so it doesn't change with the sentence.
Fixed prepositions come up all over the A2 exam. The platform drills them in real exam tasks, AI-graded across all five DUO sections.