AceStream itself does not provide content. Users create "Content IDs" or magnet links to share video streams.
For the most reliable and legal experience, you should use the official channels provided by the rights holders. Official Ways to Watch Liga de Campeones por M+ movistar liga de campeones acestream official website
Often includes the Movistar Liga de Campeones channel in their football packages. Outside of Spain: AceStream itself does not provide content
If you are determined to use Acestream for other legal content, here is how the technology works, so you understand why the "Official Website" doesn't exist: here is how the technology works