migrate psi-otr-key -> pidgin-otr-key

I have problem with migrate otr-key from psi+ to pidgin.

I copied otr-key from psi+
~ / .local / share / psi + / profiles / default / otr.keys
to the pidgin directory and I changed the name of otr-key to the pidgin format
~ / .purple/ort.private_key

and it doesnt work.
Something it's wrong

when I move orginal ~/.purple/ort.private_key

~ /.local/share/psi+/profiles/default/otr.keys

PSI + does not work with ort-key from pidgin.

What can i do?

Pidgin and Psi+, are using libotr... But there isn't the same synax of otr-key
so , I can't easily migrate otr-key between both IM.