Are you talking about the Disney Dining plan? If so, you have already paid so yes, they just scan your magic band and it removes the credits from your plan. You will have to pay for your tips, either cash, cc or you can charge them to your room with your MB.
If you use your magic band to pay, you're technically charging it back to the room. The credit card on file is then charged when the limit is reached. (I think the limits are $500 for value, $1000 for moderates, and $1500 for deluxes.)
If you use your magic band to pay, you're technically charging it back to the room. The credit card on file is then charged when the limit is reached. (I think the limits are $500 for value, $1000 for moderates, and $1500 for deluxes.)