user can take a book from library via bot. I want to send them reminder to return a book in a month. But I have another flows in this bot. And if I make reminder via wait condition, user will not get another messages, because another flow (library flow) is waiting for response. How can I make this reminder without problems in another flows?
You can try to separate or create a different flow to handle on wait only for a month to send a reminder function.
This should be independent of other flows you created, so the rest of your flows will not be affected or be left waiting as well.