When the character is ready to regain charges, the reset button next to the charge value will open a prompt to charge the stave. This will replenish the number of charges back to the default (equal to highest spell slot available). If the character has Prepared spellcasting, the player may choose a spell slot to expend to gain extra charges equal to the level of the spell slot.
This is from the readme. I think it makes sense to automate staff recharging for everyone (it happens every day, every "long rest").
Add a hook for the "rest for the night" sheet action, which will restore the staff charges to the initial number.
Technically only a single staff can be recharged like this, so if you want you can improve the implementation and set the staff charges to 0 if there's any other staff in the inventory, thereby forcing the user to manually choose which staff to pick.
This is from the readme. I think it makes sense to automate staff recharging for everyone (it happens every day, every "long rest").