Hi,
There are some issues (serious i thing) with that plugin, was the same with the original one from osclass org.
In many places there is a typo:
Instead of gdpr_osclass there is gpdr_osclass.
For example:
echo '<label style="float: none;width: inherit;"><input type="checkbox" name="gpdr_osclass" value="1"/> '.$text.'</label>';
if(Params::getParam('gpdr_osclass')!="1") {
Thanks