Error in w3 html validation

Hi, I get this error in w3 html validator.

Error: Attribute super-socializer-data-href not allowed on element div at this point.

From line 46, column 549; to line 46, column 722
<div class='the_champ_sharing_container the_champ_horizontal_sharing' super-socializer-data-href="https://www.mywebsite.com/abc/bghai/"super-socializer-no-counts="1">

also few other from this plugin.

Is it normal or it needs some attention ?