EVERMOTIONs Seceret Garden challenge, use of EPICs assets question

Hello, Im wondering if its legal to use EPICs standar content and stuff from the learning tab for challenges. EVERMOTION is hosting a challenge where one have to create a seceret garden themed scene. See for details. They have said it is allowed to use premade 3D content (§12) You can use pre-made models. You can also use licensed models and textures made by other artists / companies, but you must give proper credit for every author / company of each asset you use. .

Anyeone that know or have some experience with this useage of the standarcontent and the learningtab-content?