You need a whole slew of voltages to calibrate all the ranges, all the way up to 1kV. This is well outside of what’s easily done with simple DIY methods. Even the 2V range requires 1.999V ±0.05%.
Sure, you can use a bench power supply (linear, please!) to adjust the ranges up to 20V into the general ballpark. That’ll be good enough to test whether it’s actually working at all. But to make it useful you need another meter with at least 4.5 digits with which to precisely measure the actual voltage you’re applying.
For example, if you set your bench supply to 1.99V, connect that in parallel to both the Advance and your 5.5 digit meter, and the latter shows 1.98363V, then you’d twiddle R54 so the Advance shows 1.984V. That’s close enough to full-scale to be useful.
If truly all you have is batteries, then get some nice fresh alkaline batteries (voltage when brand new, without load: 1.6-1.7V) and measure a single one in the 2V range, using the method above. It’s not quite full-scale, so not ideal, but close enough.
But this will only calibrate the 2V range, for the higher ranges you’d need lots and lots and lots of batteries in series to get the necessary voltages.