Am i able to add external methods?

Im trying to add a scoreboard method i made into my plugin

Methods:

PHP:

createNewScoreboard()
nameScoreboard()
registerScoreboardValues()
removeScoreboard()
scoreboardAudience()

Do i have to add it as an External API for this?

(The scoreboard is in the sidebar if you wanted to know)

 

I know that, im making a custom sidebar scoreboard

But how would i implement them? Via External API?

 

Import my own API into my plugin together with the pocketmine API

 

like public function createScoreboard(){
}
?

 

Yeah

public function Scoreboard {
$this->addScoreboard()
}
Yeah. Im sorry for errors im on my phone