Hello There
I want to generate barcodes by typing the text or number to be generated as a barcode and print the amount of labels needed i left and example of custom buttons 
What is that a screenshot of?
You need to use the <BAR> line open in a printer template with whatever number/string templated on that line to create a barcode on print.
You will likely need to set a program setting from your barcode field and then use that setting in the template like;
{SETTING:LabelPrintBarcode}
And your qty could use the qty field on the print action for that template via a [?Prompt] expression below the program setting action with another prompt expression to save the barcode to program setting.