How do I use enhanced Premium collection?

You must check your "commercial purposes" against the license. For example, you cannot make a new design with these images to sell as stock.

Well, I suppose that's the reason for using stock pictures. As long as your application is in conformity with the licensing terms, you can use any picture you have licenced as you wish.

Look here for more information on licensing: https://community.adobe.com/t5/stock/links-for-licensing-terms/td-p/11366788
(Disclaimer: As always with licensing, this is my interpretation of the rules. I think they are correct and advice is based on reading and interpreting the licence terms and on fair use for both the buyer and the artist/stock company, but I cannot rule out that my interpretation is wrong. I'm not an Adobe employee).