Need some tips

Log in, get the double rewards, run dungeons if you have keys, set up auto-grind, and log out... Repeat this and you'll rack up thousands in no time.

Oh, thank you.

Basically, you get stuff from running dungeons and logging in. Nowadays, there are also a lot of events, so you can get boxes from those too. But fundamentally, you need to push through the stages first. Since you get a box for clearing each stage, I think staying logged in for a long time is also one way to go.

The 'Begging' event pops up daily, just buy everything with diamonds!! Also, leveling up the 'Divine Crusher' and opening a bunch of boxes at once gives you more EXP!!