Export SQL error

HellO! This very usefull plugin gets me error where i try export database to dump. See the screenshot:
https://disk.yandex.ru/i/qwT8hgyg4hdhdw
also, I put this as text:

CREATE DEFINER=CURRENT_USER FUNCTION wp_fn_realmedialibrary_childs (rootId INT, _useTempChildTableForCheck BOOLEAN) RETURNS VARCHAR(1000) CHARSET utf8mb4 COLLATE utf8mb4_unicode_ci READS SQL DATA SQL SECURITY INVOKER BEGIN
DECLARE sTemp VARCHAR(1000);
DECLARE sTempChd VARCHAR(1000);
SET sTemp = ‘$’;
SET sTempChd = CAST(rootId AS CHAR);
SET SESSION group_concat_max_len = 100000;
WHILE sTempChd IS NOT NULL DO
SET sTemp = CONCAT(sTemp,’,’,sTempChd);
IF _useTempChildTableForCheck IS NULL OR _useTempChildTableForCheck = false THEN
SELECT GROUP_CONCAT(id) INTO sTempChd FROM wp_realmedialibrary WHERE FIND_IN_SET(parent,sTempChd) > 0;
ELSE
SELECT GROUP_CONCAT(id) INTO sTempChd FROM wp_realmedialibrary_tmp WHERE FIND_IN_SET(parent,sTempChd) > 0;
END IF;
END WHILE;
RETURN sTemp;
END

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