Electrum mnemonic

[accountnujen]

And how do you get the key using the mnemonic phrase obtained in electrum?

[iancoleman]

The default electrum mnemonics are not bip39, see https://electrum.readthedocs.io/en/latest/seedphrase.html

I'd recommend using electrum to get the key. https://pascal-bergeron.com/en/posts/export-private-keys-electrum/