The Touch Up tool does not work the same way it did in previous versions, but you can still clone. You will be given two circles, the one in the left will be used for the area you want to "copy", so you can drag it to the position you need. The circle in the right side will be used to paste the copied area. Then, you can change the size of the circles, you just need to hover the mouse over the circle and the cursor will change to two arrows (pointing left and right), so you can click and drag it to the left or right to resize the circles.
You can also install an older version that includes the options you were used to: http://www.oldversiondownload.com/oldversions/photopad-7-40-2021-05-24.exe
Note that some tutorials or screenshots you see on the website, may be recorded using older versions and are used to illustrate some features, so the options you see in your current version may be a little different.
NCH Software formally takes suggestions or feedback about products through the form at http://www.nch.com.au/suggestions/