Go to Settings > Program Settings > Payment Screen Settings and change “Payment Screen Values” to a comma separated list of the values you want.
So for example, if you want 5,10,20,50,100, add as follows:
If you want to add a currency symbol, add the format of the currency at the end like
It is also possible to use dynamic values by adding
* in front of the values, for example if you want to show the next $5, next $10, etc. You cam also mix and match - for example, the following will show the next values for $1, $5, then always show $10, $20 and $50:
As you can see from the example on my system where I use dynamic values for all amounts, the values on the buttons will change as the total amount changes (I apply discounts to change the amount to illustrate):