Importing data from excel to identification toolbox to find the Transfer Function of a real system

Hello! I have some data of a genetaor's RPM. I want to import these data to MATLAB's identification toolbox in order to find a transfer function for my system.

The issue is when I open the toolbox, I can't figure out how to import my data. Any help would be appreciated.

[dpb]

I don't have the given TB/App, but if it doesn't provide a menu to load data from a file (I'd think it would, but maybe it presumes data are already loaded), then

data=readmatrix('YourExcelFile.ext');

first from command line. Or there's the "Import Data" button feature (the down-pointing green arrow)...