Once you're on the Expo floor, go to any booth to find the option "Exchange Business Card."
Clicking on it gives you the option to type your message in the dialogue box that pops up. You can edit the text and send a personalized message to the exhibitor. Your details and messages will be sent to the Exhibitor and you will receive the details of the exhibitor via email on your registered email ID.
For getting more familiar with the Expo area, go through this article.
Reach out to email@example.com for any issues.