When printing a 4x6 shipping label in SendPro Online on the Brother QL-1100 printer, the message "The roll of labels or tape inside the machine does not match the one selected in the application" appears.
From the print preview screen of the label, complete the following based on your browser. Once you print with these settings, the paper size will remain as the last used.
If using the Print Using System Dialog option:
UPDATED: January 29, 2021