Welcome to the forum @josebranm
This is a common question, which is addressed somewhat by this post.
If you look at your acceptance email, you’ll notice this section:
Usually, if a nomination isn’t added to Pokémon Go within 48 hours, it’s because it doesn’t meet the proximity requirements for that game. You can read more about the proximity rules here.
If you can’t figure out how to check whether your nomination doesn’t comply with the proximity rule, you are welcome to post the name and coordinates of it and someone will give you a visual demonstration of why it isn’t appearing.