Hello,

Is there a way for a homebrew feat to add ki points?

No. No homebrew thing can add or change base class features.

You can however, make a feature with actions set with limited uses and recharge on short rest to represent extra ki. This will allow the player to tick them off as used but they will be in a separate place than their normal Ki pool.

I do something like that with this homebrew magic item.

So did I with these:

Master Bōdei’s Handwraps

 

 

Wondrous Item, legendary (requires attunement by a Monk)

 

The cloth handwraps used by Master Bōdei himself have been passed down from Senpei to Kōhai for generations. They wrap the forearms and fists with enough fabric left to drape from them in strips that hang to the ground.

These magic hand wraps come with 6 charges. These charges count as Ki for you. They regain all of their expended charges each day at dawn.

While you are wearing these handwraps, and attuned to them, you gain the following benefits:

• These wraps cover your forearms to the elbows granting you additional protection. You have a +2 bonus to your Unarmored Armor Class.
• These wraps add additional power and precision to your blows. You have a +2 bonus to attack and damage rolls made with your unarmed strikes.
• The additional strips of fabric that hang from them can be used to lash out at opponents. The reach of your unarmed strikes can extends by an additional 5 ft.
• When you take the attack action on your turn, you can choose to make a single special attack in place of your normal attacks. You strike out with the extra strips of fabric that hang from these wraps against a creature within 30 feet.
   Make a single Unarmed Strike against the target. On a hit, the attack deals an additional martial arts die of damage on top of the usual damage from your unarmed strikes, and if the creature is Large or smaller, you pull the creature up to 10 feet closer to you.

Notes: Damage: Unarmed Attacks, Bonus: Unarmed Attacks, Bonus: Unarmored Armor Class, Bonus: Melee Reach, Monk, Damage, Buff, Combat, Warding, Wristwear, Handwear

—IamSposta

Those are great ideas. Thanks all!