Minecraft wiki entry for enchant, associated text: Specifies the enchantment level. Should be not greater than the maximum level for the specified enchantment[note 1]. If not specified, defaults to 1.
Must be a 32-bit integer number. In Java Edition, it must be between 0 and 2147483647 (inclusive). In Bedrock Edition, it must be between 1 and 2147483647 (inclusive).