Spouse Visa Extension

Hi, apologies if this gets asked a lot but I’m a bit overwhelmed by all the information online! My spouse visa expires December 2nd, can someone please let me know when I need to submit my application?

From what I gather the earliest is 28 days before it expires (so November 4th) and as long as I have an application pending I am still able to live and work in the U.K.?

Any help and advice is much appreciated!!