public function get_sequential_id() {

		/**
		 * Filter certificate sequential id formatting settings.
		 *
		 * These settings are passed as arguments to `str_pad()`.
		 *
		 * @since 6.0.0
		 *
		 * @link https://www.php.net/manual/en/function.str-pad.php
		 *
		 * @param array {
		 *    Array of formatting settings.
		 *
		 *    @type int    $length    Number of characters for the ID.
		 *    @type string $character Padding character.
		 *    @type int    $type      String padding type. Expects a valid `pad_type` PHP constant: STR_PAD_RIGHT, STR_PAD_LEFT, or STR_PAD_BOTH.
		 * }
		 * @param LLMS_User_Certificate $certificate Instance of the certificate object.
		 */
		$formatting = apply_filters(
			'llms_certificate_sequential_id_format',
			array(
				'length'    => 6,
				'character' => '0',
				'type'      => STR_PAD_LEFT,
			),
			$this
		);

		$raw_id = $this->get( 'sequential_id' );

		$id = str_pad(
			(string) $raw_id,
			$formatting['length'],
			$formatting['character'],
			$formatting['type']
		);

		/**
		 * Filters the formatted certificate sequential ID string.
		 *
		 * @since 6.0.0
		 *
		 * @param string                $id          The formatted sequential ID.
		 * @param int                   $raw_id      The raw ID before formatting was applied.
		 * @param array                 $formatting  Array of formatting settings, see `llms_certificate_sequential_id_format`.
		 * @param LLMS_User_Certificate $certificate Instance of the certificate object.
		 */
		return apply_filters( 'llms_certificate_sequential_id', $id, $raw_id, $formatting, $this );

	}