Ragnarok Mobile Episode 7 increases max base level to 160. Complete the Hero’s Adoramus quest to unlock your additional 20 levels.
You will receive the quest at base level 140.
Once you have the quest the first thing to do is to head to Yuno. The quest chain is quite straight forward.
Talk to a couple of NPCs in Yuno, get teleported to the Unlimited Library, interact with the Book of Yimir.
Get transformed into a novice (just a cosmetic change). Defeat monsters and progress through your class tree.
You’ll eventually fight and defeat the demon monster Morroc. Congrats now time to grind for those newly unlocked levels.