How can I create event in User.com?

You can create event:
1) using this instruction: https://docs.userengage.com/what-are-events-and-how-to-create-them

2) or do it via Data Collector: https://docs.userengage.com/module-guide-data-collector

3) or do it via GTM: https://support.google.com/tagmanager/answer/7679219?hl=en