hello,
What’s the function of Ticket button in payment screen please?
If there is a customer attached to the ticket and customer wants to pay ticket and remaining balance together you can use Ticket button to switch modes to settle only ticket or whole balance.
Can you explain more detail?
For example your customer already have $100 balance and you’ve created a new $40 ticket for that customer. When you are settling it customer gave us $100 and said “decrease change amount from my prior balance”. When you use ticket button SambaPOS will first settle $40 and decrease remaining $60 from his account.
That was a very old (and forgotten) feature and I think most people even didn’t noticed that 
While typing it I think we can reimplement it with new Payment Processors feature.