How to convert line with UNIQUE INDEX key words from mySql to H2

CREATE TABLE IF NOT EXISTS Account (
  `userId` INT NOT NULL AUTO_INCREMENT,
  `first_name` VARCHAR(45) NOT NULL,
  `last_name` VARCHAR(45) NOT NULL,
  `email` VARCHAR(45) NULL,
  `ICQ` INT NULL,
  `home_address` VARCHAR(45) NULL,
  `work_address` VARCHAR(45) NULL,
  `skype` VARCHAR(45) NULL,
  `additional_info` VARCHAR(450) NULL,
  PRIMARY KEY (`userId`))
 UNIQUE INDEX `userID_UNIQUE` (`userId` ASC)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='Account';

how to convert this line: UNIQUE INDEXuserID_UNIQUE(userIdASC) from mySQL syntax to H2 syntax ?