Not Recognizing Manually Created Symbolic Links

I am building my add-on in an external folder but I do not use cscart-sdk for it. I just typed this command in my console ln -s /root/sendsms_module/app/addons/sendsms /var/www/html/ I have some issue with the sdk so I cannot use it. My problem is that my addon does not show in the add-on directories in the platform. I created a test add-on in in the app/addon folder without using an symbolic link and it got recognized. What is my problem? I checked the addon.xml and it looks good to me

<?xml version="1.0"?>

	Send sms with our services

Have your hosting verify that the Apache method for following Slinks is enabled.