What if I don’t have a credit card to pay for my bags ? Is there a machine that I can use to put cash in and use it for my check in bags ?

You would need to go to a ticket counter and pay someone Which airline?

There is a Credit Card dispensing ATM type machine. At least there was you would put whatever set amount of cash in and it would charge it to the charge card and dispense a credit card loaded with the money that you inserted it into the ATM. Or you could go to any p convenience store Walmart Target Etc that sells gift cards and get a GreenDot card and you load it with the desired amount