When should I apply for a visa extension if my current COVID extension ends on July 20th?

The user is currently on a COVID-related visa extension set to expire on July 20th and is inquiring whether applying for another extension now would start the new extension from the expiration date (July 20th) or from the application date. Comments suggest that typically, if applying for an extension for the same reason, the new extension would be appended to the existing expiration date. However, it's recommended to apply closer to the expiration date.