protect single file in htaccess

You can protect a single file in htaccess using the following,

-- First create a file named ".htaccess" and add the following line of code,

AuthName "Only Admin Can Access"
AuthType Basic
AuthUserFile /path/to/.htpasswd
require valid-user

-- Second, create a file named ".htpasswd" and add the username and password as,

user:$apr1$yUfasdxy$712kJrWjFHsRbOLm8sHnl0

Note: Use any password generator tool to create the htpasswd for eg, https://www.hscripts.com/tools/htpasswd/index.php