altText property
A description of the icon used for accessibility.
If unspecified, the default value Button is provided. As a best
practice, you should set a helpful description for what the icon displays,
and if applicable, what it does. For example, A user's account portrait,
or Opens a new browser tab and navigates to the Google Chat developer documentation at https://developers.google.com/workspace/chat. If the
icon is set in a Button, the altText appears as helper text when the
user hovers over the button. However, if the button also sets text, the
icon's altText is ignored.
Optional.
Implementation
core.String? altText;