The official Pokémon movie website has updated. Translations follow:

"The Oración Theme: Let's Walk Together" is Now Available for Download!

Asuca Hayashi's "The Oración Theme: Let's Walk Together",
The ending theme song for "Pocket Monsters the Movie: I Choose You!", which premiered today, is now available for download!

Everyone that buys the special package collection on Recochoku or mora will also receive a special wallpaper
for their smartphone or PC.
Make sure to download this and get the wallpaper!
https://erj.lnk.to/cdukJWN

Source: http://www.pokemon-movie.jp/news/?p=2969