First thing , In Qlik Sense Label Name is not dynamic or function basis. Secondly , I have tried on my side , It can take one single space as " Payment" but not more than 1. The statement you have written above chr(32)+chr(32)+"Payments" , works in Qlik View but these things doesn't work in Sense . the point here is full replica Qlik View to Qlik Sense is not possible because Qlik Sense a new generation visualization and it has its own way of visualization.
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You could try it with another white-space character like chr(160) which you could create in a table or textbox which you could then export or you used a different tool like excel or an editor to create them - and then copying these charcters together with "Payments" into the label.
To get an overview about white-space take a look here: Whitespace character - Wikipedia, the free encyclopedia.