How to create a post in a group using the classmates api?

Question

PHP

Hello. The task is to publish posts in the group using api classmates (although it doesn’t matter if there is an alternative).
Their api documentation is, to put it mildly, not very good, it’s difficult for me, as a below-average person, to understand it. Can you give me links to some tutorials, where it is more or less clearly described how to implement this task step by step?
Thanks in advance to all who respond.