For the dynamic menu in slack my servers respond back the result in 4-5 second(as there is some computation which will take some time) but it seems like the timeout of the request from slack app is around 3 second and that's why in the drop-down it shows a message "Nothing could be found."
Is there a way to increase the request timeout time?
The limit for responding to requests from the Slack API is fixed at 3000ms. There's no way to adjust this.