Hello, please help, if possible.

I need to import a FTC (feathercoin) private key originally from electrum-ftc desktop wallet. That one will not connect to the network no matter what I do. Feathcoin-QT (the full node wallet) is connected to the network, but there is no apparent way to import a private key (the "export/backup" option is easy to find, but not import), and no matching info on Google.

Earlier, I tried Edge Android wallet (error message every time when importing), and the few others supporting FTC, none worked. This has to be possible, how? Thank you.