There are 2 methods:
1. If you have a house (the best Feng Shui is Zi Qi Dong Lai), click on the housekeeper to view the pet room → train the summoned beast → XXX (the Pet's name) Level Your BB will be upgraded immediately
2. The following locations are the upgrade areas for different levels of BB
Scene/Level/Experience
East Bay Level 0 414
Wreck Level 1, Level 2 724
Wreck Level 2, Level 4 931
Donghai Cave Level 4, 931
Jiangnan Wilderness Level 6, 1138
Big Wild Goose Pagoda, 1st floor, 8 levels, 1345
Dayan Pagoda, 2nd floor, 12 levels, 1759
Big Wild Goose Pagoda, 3rd floor, 16 levels, 2173
Dayan Pagoda Tower 4 floors, 20 levels, 2587
Big Wild Goose Pagoda, 5 floors, 24 levels, 3001
Dayan Pagoda, 6 floors, 28 levels, 3415
Datang Kingdom, level 11, 1656
Level 20 outside the Tang Dynasty 2587
Mowang Village Level 32 3829
Putuo Mountain Level 36 4243
Pansiling Level 38 4450
Undersea Labyrinth Two, Level 35, 4140
Undersea Labyrinth Three, Level 37, 4347
Undersea Labyrinth Four, Level 40, 4657
Moon Palace, Level 48, 5485
Underworld Labyrinth Two, Level 37, 4347
Underworld Labyrinth One, Level 40, 4657
Underworld Labyrinth Four, Level 43, 4968
Underworld Labyrinth Three, Level 46 5278
Beiju Luzhou Level 54 6106
Level 58 6520 on the first floor of Dragon Cave
Level 62 6934 on the second floor of Dragon Cave
The third floor of Dragon Cave is level 68 7567
The fourth floor of Dragon Cave is level 72 7969
The fifth floor of Dragon Cave is level 76 8383
The sixth floor of Dragon Cave is level 80 8797
Level 84 9211 on the seventh floor of Dragon Cave
Level 62 6934 on the first floor of Phoenix Nest
Level 66 7348 on the second floor of Phoenix Nest
Phoenix Nest Level 70 on the third floor 7762
Level 74 on the fourth floor of Phoenix Nest 8176
Level 78 on the fifth floor of Phoenix Nest 8590
Level 83 on the sixth floor of Phoenix Nest 9108
Xiao Leiyin Temple Level 121 13104
Get 80% of the experience by being 1 to 5 levels below the full experience level.
If you are 6 to 10 levels below the full experience level, you will get 70% experience.
If you are 11 to 15 levels below the full experience level, you will get 60% experience.
1 less than the full experience level. 50% experience will be gained from levels 6 to 20.
Experience will start to drop when the level is 11 or more levels above the full experience level, and 80% of the experience will be gained when the level is 11 to 15 more levels