How to activate arceus

ok I’ve don damiana quest and I have been through holon and did its small quest but I haven’t gotten a call saying that something was going on

Here’s the guide says:

After finishing the Original Dragon, Holon, and Dream World quests, go back to Perfection Base (near Black Market). Once you read the note, return to Amphitrite City to the cave where Mew and the Timeless were, and go through the Hoopa portal which you previously used to get to Giratina. Just follow the path the same way you did for Giratina, and on the way, various trainers and legendary pokemon will stop you. Eventually, you will get back to the Throne of the Hegemon, and Reukra will battle you, after which Arceus will be summoned which you can catch.NOTE: Arceus has Perish Song, so be very careful. Also, you cannot heal between battling Reukra and catching Arceus. Also, this quest must be finished before the elite 4 can be rematched I believe. Note:It is recommended to keep your Pokemon level around 100 to 110.

So no call will come,you have to go to perfection lab and read the note.

And for further question abbout post game,use this-

ok thanks