There are a few foot shifter ones in Europe that have mostly superficial pedals just to meet certain legal requirements. there was even a pedal version of the MB5. Most are very short pedal arms that lock into place and behave effectively as pegs while you're shifting/braking by foot. Manual mopeds were never allowed as mopeds by US laws so as mentioned they're nearly nonexistent in the US>
But for actual pedal mopeds that had a manual clutch version, most common are the sachs, puch and zundapp mopeds which had 2 and 3 speed grip shifters. Old vespa and lambretta scooters (and the indian derivatives like Bajaj) usually over 100cc and definitely not mopeds but they used manual grip shifters too.
The puch manual gripshift engine is the Z50, it's a manual 2 speed kickstart but unfortunately not the same bolt pattern as the ZA50 and e50 we got in the US. you can make adapters though, and some people have.
The sachs is the one you'll see most in the states, because it's easier to import a motor than a whole bike and the 2 /3 speed motors are a direct bolt-in replacement for the very common sachs 505 engines and can easily be found and purchased on ebay Germany in the $200 range. Really pretty inexpensive when you consider folks paying significantly more for just high end clutches on other engine platforms. I've had a few personally and built several others with or for friends. It's definitely fun, but after many years of manual clutching I just converted my main sachs back to auto for simple mindless commuting. (while simultaneously building up 2 other manual 2-speeds...)