src/properties/class-papi-property-editor.php
protected function reove_mce_buttons() {
		for ( $i = 0; $i < 4; $i++ ) {
			$num = $i === 0 ? '' : '_' . ( $i + 1 );
			remove_filter( 'mce_buttons' . $num, [$this, 'mce_buttons'] );
		}
	}
protected function reove_mce_buttons() {
		for ( $i = 0; $i < 4; $i++ ) {
			$num = $i === 0 ? '' : '_' . ( $i + 1 );
			remove_filter( 'mce_buttons' . $num, [$this, 'mce_buttons'] );
		}
	}
Remove filters that filter TinyMCE buttons.