In the file plugin/admin/activation.php around line 67 replace

'Category'      => 'free',
'Build'         => 'premium',
'Title'         => 'OnePress Zero License',
'Description'   => __('Please, activate the plugin to get started. Enter a key
                     you received with the plugin into the form below.', 'plugin-sociallocker')

with

                'Category'      => 'paid',
                'Build'         => 'premium',
                'Title'         => 'OnePress Premium License',
                'Description'   => __('Thank you for purchasing SocialLocker!', 'plugin-sociallocker'),
                'Name'            => 'premium_license',
                'Expired'        => 1729334825,
                'KeyBound'        => 'no_thank_you',
                'Key'            => '6354e192-8fb0-4a44-a42d-950b254d3554',
                'Embedded'        => true  

Now go to the plugin menu in dashboard and deactivate the plugin. Reactivate the plugin and you should now be good to go.

To be on the safe side, also edit sociallocker-next.php and comment out lines 62-65 and 67 which will stop it being able to connect to the api.

Lastly, activate a trial license on a test site and you can update it to the latest version.