Critical Error after Activating Plugin

I’m trying to install this plugin because the Theme I purchased requires it.

I’m stuck on the link account screen. If I press skip, it does nothing, if I press Allow & Continue, then I get a critical error. My error log says this:

[Thu May 13 05:13:10 2021] [error] mod_fcgid: stderr: PHP Fatal error: Uncaught Error: Call to undefined method stdClass::has_trial() in /home/www/pruebas.clinicabienestarlaboral.com/wp-content/plugins/salon-booking-system/freemius/includes/managers/class-fs-plan-manager.php:155