There is no adhoc limit for the number of user who can chat with your chatbot. This only depends on how many message credits your subscription has and how many messages each user sends to the chatbot. We usually advice that single conversation on average has 10-15 messages, however this may vary depending on the use case. In case your subscription has 500 credits, you can have 50 conversations with 10 messages each, or 25 conversations with 20 messages each