https://www.cnet.com/tech/services-and-software/6-clever-gmail-tricks-to-minimize-regret-frustration-and-spam/

By simply adding a + to the end of your username (but before the “@”) you can create infinite variations of your Gmail address. For example, username+junkmail@gmail.com will direct email to your main address without giving it away to spammers. You can then filter messages containing “username+junkmail” into your junk or trash folder so you never have to be bothered to delete them again.