When I run a mysql command in a script, "Warning: Using a password on the command line interface can be insecure" is displayed

My name is Ito and I am an infrastructure engineer. We use a script to back up our database every night. The version of MySQL that I often use is 5.5, but I had an opportunity to use 5.6, and as usual, when I run the mysql command in a script, I get the message "Warning: Using a password on the command line interface can be insecure” is displayed.