public function get_default_fields() {
		$sections = [];

		$sections['general'] = [
			'title'      => __( 'General', 'dozent' ),
			//'desc'       => __( 'General Settings', 'dozent' ),
			'icon_class' => ' dicon-cog',
			'callback'   => '',
			'fields'     => [
				'maximum_students' => [
					'type'        => 'number',
					'title'       => __( 'Maximum Students', 'dozent' ),
					'label_title' => __( 'Enable', 'dozent' ),
					'default'     => '0',
					'desc'        => __( 'Number of maximum students can enroll in this course, set zero for no limits',
						'dozent' ),
				],
				//course_levels
			],
		];

		$sections['curriculum']      = [
			'title'      => __( 'Curriculum', 'dozent' ),
			//'desc'       => __( 'Build your course with Dozent course builder.', 'dozent' ),
			'icon_class' => ' dicon-book',
		];
		$sections['intro_video']     = [
			'title'      => __( 'Intro Video', 'dozent' ),
			'desc'       => __( 'A quality introduction video shows that you are prepared and provides a good first impression for your students.', 'dozent' ),
			'icon_class' => ' dicon-play2',
			'callback'   => [ $this, 'intro_video' ],
		];
		$sections['information']     = [
			'title'      => __( 'Information', 'dozent' ),
			'desc'       => __( 'Course general information like course duration, benefits of the course, requirements, target audience.', 'dozent' ),
			'icon_class' => ' dicon-check',
			'callback'   => [ $this, 'course_information' ],
		];
		$sections['attach_products'] = [
			'title'      => __( 'Attach Product', 'dozent' ),
			'desc'       => __( 'Attach WooCommerce/EDD product to sell the course.', 'dozent' ),
			'icon_class' => ' dicon-product',
		];

		/*
		 * TODO: need to move it pro version
		$sections['prerequisites']   = [
			'title'      => __( 'Prerequisites', 'dozent' ),
			'desc'       => __( 'Student have to must complete give courses before enrol this course.', 'dozent' ),
			'icon_class' => ' dicon-clipboard',
		];
		*/
		$sections['instructors']     = [
			'title'      => __( 'Instructors', 'dozent' ),
			'desc'       => __( 'Take courses by multiple instructors.', 'dozent' ),
			'icon_class' => ' dicon-instructor',
			'callback'   => [ $this, 'course_instructors' ],
		];

		return apply_filters( 'dozent_course_settings_tabs', $sections );
	}