can't rank up my champs

why i can't rank up my champ from rank 3 to rank 4, while my catalyst is sufficient for it.

Comments

You are lvl 50. Lvl up to increase your t4 alpha inventory. You can see it shows 3/4

Gotta be level 60 or buy the sigil.

LOL... I didn't even realize this was a thing.

Time to start doing story content with XP boosts going.

Start grinding solo raids and daily xp.