Premium Purchase Question

I’d like to purchase premium but I’d like to use wp-crm across multiple independent sites (I have 2 and am expanding to 4.) These are all my private websites, I am not a developer. Is domain name configurable if I purchase premium? Honestly, if I want to spend hundreds of dollars for contact management I’ll go to a service, I like this because I can do things locally and inexpensively.

https://wordpress.org/plugins/wp-crm/