Timestamps for chats in ChatGPT

Messages may GENERATE a timestamp but Apple won’t allow us to create a simple text replacement that pastes a dynamic timestamp with a quick short cut, such as ‘;dt’ that auto-expands into something like ‘260329 | 03:25:46 AM CT’. Of course, I could buy TextExpander for $30 to do this but. . . really?!? This is so basic. It irks me that it’s not built in to the OS.