Use the FormData API to populate a form field with a previously set value in local storage.
Use the Fetch API to submit a form, adding extra data with the FormData API.
Mark a form field as required with the "required" attribute.
Limit the range of values that can be entered into a number input.
Use the setCustomValidity function to apply a custom validation message.
Validate that at least one option is selected in a group of checkboxes.