Hi,
Yes, Tickets Plus is replacing the other ticketing plugins. They are combined into it and we created a license for Tickets Plus for all users of the 4 original ticketing plugins.
So you should already have it in your account.
We have this guide to changing over to Tickets Plus
https://theeventscalendar.com/knowledgebase/moving-to-event-tickets-plus/
Looking at your account it appears you might only have one license for Tickets Plus, but should have two. If that is the case email us at support(at)theeventscalendar.com and we can help out.
Thanks