I cant get my blue essence from my old runes

Hello Riot

you guys have been doing a great job making this game better, but after the 7.22 update, I didn't receive my blue essence from my old runes, also I read some discussions between players and it seems like there is a "runes mission" and I can't find it in my game too. Please fix it for me or give me some solutions in order to get my blue essence from old runes, I am so appreciated!