When connecting to PostgreSQL I get an Authentication Failed error

psql: FATAL:  password authentication failed for user "your_username"

An Authentication Failed error occurs when:

• You connect to the wrong database cluster.
• You use the wrong username or password.

If you are getting this error, check the cluster and username/password combination you’re using. To better review changes, we recommend the flags format to modify the connection string. For more on the flags format, see How To Connect to PostgreSQL.