Avoiding duplicate records with multiple requests

I have a chatbot system that creates a record in the table with user information during the first interaction. However, when the user sends multiple messages in a short period of time, my code cannot check if there is already an open session because it is still being processed. As a result, it creates multiple sessions instead of adding messages to the first one, causing duplicate records. I have already tried to use a middleware, but the problem still persists. I would like some help on how to solve this issue.