That is telling you the database connection details are incorrect. You need to check all four of them again. It’s possible you need to specify a host name in place of localhost (the thing they say there is a 99% chance you won’t need to change.) Since my database is on a different server, I need to change that 100% of the time.
Only you will be able to verify that your connection details are correct. Right now, they are not and that’s what the message is telling you.