I am new to Krita and I cant find out how to paste frames.
Everywhere I look it just writes about copying them, but what use is copying if i can't even paste them?
I'm using Krita 3.3.3

I assume you mean frames in the animation timeline docker.

Perhaps it should say 'Copy Selected Frame To Here' because that's what it does. Click on the frame you wish to copy, to select it, then right-click the destination frame you wish to copy it to and click the Copy Frame option. The frame you first selected will be copied to the destination frame. If the destination frame has content, you will be presented with a Remove Frame option so you need to click that to empty it first.

You can move a frame by dragging it to a destination frame, which will be overwritten by the moved content. The frame you moved will then be empty of content.

It doesn't seem to work on Krita 4 (OSX High Sierra)...

Which version of krita are you using?
In what way doesn't it work? What do you try to do and what happens? What doesn't happen?

I select a frame, then with the right mouse button choose a blank layer and click on Copy Frame. What happens is that the last drawn frame is always copied and not the one I selected.

I am on OSX High Sierra, Krita 4.

Thanks!!!

(When you say, "... choose a blank layer ...", I assume you mean "choose a blank frame". )

You're right, this is my fault. I've only ever done animation by copying a frame to the next frame (simple stuff).

This is useful: https://docs.krita.org/Animation

To do a copy of any frame to any other frame, you need to do Cntrl-click(hold) then drag to the destination frame. Sorry about the confusion.

Also, there may be a problem with Remove Frame (which I've made a bug report for). If Remove Frame doesn't work, just click drag the frame to move it to beyond the end of the animation to a 'dump' location so it's out of the way. You can drag many frames to this same dump location if you need to.

Thanks! That's it! On OSX is the Option/Alt to copy the selected frame (instead of Cntrl).

And also thanks for the link!

By the way, I don't have the 'remove frame' issue.