Hello,

You can go to Dashboard > Theme Settings > Typography > Advanced > there you can add new Rule > in that you can select Menu related elements > then you can define the Text Transform option as Lowercase and can also define other Font Styling related options: https://snipboard.io/j2IFPJ.jpg

You can read more about it here: https://xtemos.com/docs-topic/advanced-typography-settings/

Best Regards