Hey Naveen,
Thanks for reaching out.
The QR Codes are just a “scannable” way to check-in folks at the door to your event. They can print out a ticket or show the ticket on their smartphone; then, using a free QR Code scanning app—of which there are many out there for both iOS and Android—you can scan the QR Code that is on the ticket.
When scanned, this will “check-in” that ticket so that you can track attendees and ensure that only one attendee shows up per one ticket.
While we do not have a video at this time, this knowledgebase article covers much of this process and should be helpful ? https://theeventscalendar.com/knowledgebase/managing-your-orders-and-attendees/
As for “over the counter” ticketing, our plugins do not offer any such features or any sort of “offline” mode. The ticket sales from our plugins only happen on the website and then the tickets are emailed to the purchaser.
I hope this information helps!
George