code/models/editablefields/EditableFieldHeading.php
public function getFieldConfiguration()
    {
        $levels = [
            '1' => '1',
            '2' => '2',
            '3' => '3',
            '4' => '4',
            '5' => '5',
            '6' => '6',
        ];

        $level = ($this->getSetting('Level')) ? $this->getSetting('Level') : 3;
        $label = _t('Moo_EditableFieldHeading.LEVEL', 'Select Heading Level');

        return [
            new DropdownField($this->getSettingName('Level'), $label, $levels, $level),
        ];
    }
public function getFieldConfiguration()
    {
        $levels = [
            '1' => '1',
            '2' => '2',
            '3' => '3',
            '4' => '4',
            '5' => '5',
            '6' => '6',
        ];

        $level = ($this->getSetting('Level')) ? $this->getSetting('Level') : 3;
        $label = _t('Moo_EditableFieldHeading.LEVEL', 'Select Heading Level');

        return [
            new DropdownField($this->getSettingName('Level'), $label, $levels, $level),
        ];
    }
Get extra configuration fields.

@return array