iTerm2 swap panes keyboard shortcut

If you mean switching focus between panes:

⌘ + ⌥ + ← and ⌘ + ⌥ + →

or

⌘ + [ and ⌘ + ]

If you mean swapping the positions of the panes, it can only be done from the right-click menu:

1. Right-click pane to swap from, it turns red
2. Click on pane to swap to

There is no keyboard shortcut for this according to gitlab issue

Correction for the second part of the selected answer:

If you mean swapping the positions of the panes, it can only be done from the right-click menu:

1. Right-click pane to swap from, it turns red
2. Click on pane to swap to There is no keyboard shortcut for this according to gitlab issue

You can set it on your own.
Go to iTerm2->Prefrences->Keys.
On the bottom you will find a plus sign - press it to add a keyboard shortcut.
You can choose from a variety of actions - including "swap position with split screen".