Tips on how to avoid these zits  

Circular objects do not like the seam position 'standard' I get the best results with:

Posted by: @zimmermann-felix99

This was my third attempt at this print. I'm new here, but I already read a lot about the problem Zits
at simplify.support and tried many options
... but unfortunately, despite many changes, they have only become minimally smaller.

I use original Prusa PLA

 

Printer settings

Does anyone have an idea what I should change?

 

 if things don't get much better, also try to reduce retract in filament settings.

Posted by: @zimmermann-felix99

[...] Does anyone have an idea what I should change?

Those are most likely caused by the z-seam created as the nozzle is moved from layer to layer. You can move the seam around and try to tuck it in corners, but you can't get rid of it completely. Looking at your pictures, it looks like you have the z-seam position set to Random, which will scatter the dots all around and create those zits. You might have better luck with other options: Nearest and Aligned will try to keep the seams in corners (which won't work with cylindrical shapes with no corners). Rear will align them along the rear of the part.

You may be able to rotate the part to minimize appearance. In some cases, you just have to live with it and be prepared to sand it down after printing.

The upcoming PrusaSlicer update will include more options I believe. In the meantime, you can reduce the distortion as much as possible by calibrating your extrusion multiplier for each filament to reduce the size of the zits. The less over-extrusion, the smaller they'll be. With a bit of work and patience, you can greatly reduce the appearance. The filament you choose will also affect how obvious the seam is.

FYI - A good screen capture program can be much easier to use. I'm fond of Monosnap, free for individual use.

@bobstro

is the resolution of "Monosnap" better than the "snipping tool" solution integrated in windows?

@oxygen

I chosed random.

@karl-herbert

I will test it. Thanks

As said by bobstro and me that could be the  main cause of your problem (best options are aligned or rear) 

Posted by: @karl-herbert

[...]is the resolution of "Monosnap" better than the "snipping tool" solution integrated in windows?

Monosnap captures the native resolution. Not sure about shipping tool, but Monosnap is cross-platform (incl. Linux) so I like to recommend it. It also has some nice annotation tool.

@bobstro

Windows Snip&Sketch (the successor to Snipping Tool) is really handy now, I set it to activate on Print Screen button press, also works in games. You can do annotations too.

Not multiplatform though.