Is it possible to copy paste prototype interaction?

Granted, this was in February (it’s September now), but unlike @Gleb wrote above, it actually IS possible to copy/paste interactions from one frame to another in Figma!

Not sure was this possible in February, when this question was originally posted & answered, but if you want to copy an interaction from a certain frame, here are the steps to do that:

1. Select the frame & make sure you have “Prototype” tab active from the right sidebar
2. Select the interaction, that you want to copy. This is the tricky part: you don’t want to activate the “Interaction details”-popover from the middle, nor especially don’t want to select the “➖” -button, as it will remove the said interaction. I’ve found that the easiest way is to aim for the empty (approx. 10dp?) margin area in the left edge of the sidebar (visible as the lighter blue area, marked with a magenta arrow, in the picture attached):
   
   When selected, the entire interaction row has the same light blue color, as in the picture above.
3. Press Cmd/Ctrl + C (or select “Copy”, from the toolbar menu), while the interaction is selected.
4. Select the frame, to which you want to copy the interaction to
5. Make sure, that you have the “Prototype” tab still active, while the target frame is selected. Paste the interaction. It should now appear under the “interactions” in the target frame.

Edit: Tested in the Figma browser version, and verified that this same method works there too! (the description above was originally for the desktop app)

Edit 2: Apparently it is possible to copy and paste multiple interactions from the same frame/source with this method! Just have Shift (⇧) pressed, while you select the interaction(s) to select multiple to copy.