Create a .htaccess file under 'wd' directory. and place the following statements in that .htaccess file.

AuthType Basic
AuthName "Password Required"
AuthUserFile /usr/local/password/passwd.file
Require user <username>
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Use the command htpasswd to create password file.

htpasswd -c /usr/local/password/passwd.file <username>
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Finally add AccessfileName in the virtual host apache configuration.

<virtualHost>
ServerName  www.xyz.com
DocumentRoot <root-Dir> 
AccessFileName .htaccess_www.xyz.com
</virtualHost>
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