What wallet are you using?
Bitpay - I use that for the forums and for mining rewards from Kano.is pool
I use a ledger for everything else so that is not useful here as I need to sign transaction from the bitpay address.
I tried to add my private key to Electrum from Bitpay but it wont take it. Note that Electrum does accept private key from ledger
I am not sure if it is because bitpay uses BIP44 not BIP32?
I have done mining for years and have used many wallets but have never used or found myself in need of signing a transaction so I apologize for my ignorance in this matter.