From Aura Kingdom Wiki
As your character's EXP bar reaches certain milestones, they will earn points to spend on the Envoy's Path. The Envoy's Path contains potent passive abilities that boost stats, grant new skills, and modify existing skills.
The number of available points is displayed in the Points section at the bottom-left. Previously assigned Envoy's Path points can be reset, though each reset costs gold.
New bonuses can only be selected from squares directly adjacent to squares you have already unlocked. To unlock a square, left-click on a shaded icon, then click Confirm. If you're having second thoughts (and we all do now and then), you can click Undo to reset any points you've allocated during the current session, as long as you haven't yet hit Confirm to finalize your choices.
Be sure to plan your course carefully, as there are powerful bonuses and skills available at the outer edges of the Envoy's Path. Also, keep in mind that some skills you will come across require certain secondary weapons to use.
Each Envoy's Path is unique for each class. An Envoy of Gaia will gain Envoy's Path points to spend at every third level, starting from level 3.
To calculate how many Envoy's Path points you have, divide your level by 3 and round downwards. As an example, if you are level 50:
50 / 3 = 16.666, so 16.666 is rounded down to 16.