Cancel Ticket in SambaPOS 3

Does anyone know how to cancel a ticket in Samba POS v3.35? Also is there a solution for adding discount on item level and make it variable (same as change price)?

Thank you…

Not sure about V3 but you can definitely do that in V4. Why not upgrade to the latest version theres not much support left for V3 and soon V5 will be released with even more updates

I am fairly confident that some features needed to do this are not available in v3. You should upgrade to v4 version 3 is 2 major releases behind now and will severely limit what you can do especially when reading about features on the forum.