Hi Aleksey, 

thank you for your message. 

Please consider that this function is already available: with WebSite X5 Pro you can choose whether you want to manage the subscriptions manually or automatically. Please find here the link to our guide about this aspect: http://help.websitex5.com/en/v2019.1/pro/es_area.htm

Please let me know if I can be of further help. Kind regars.