It is the site blockchain.info that asks me to finalize a transaction because my funds are on an imported address is I would like to put them on my wallet
You imported the address only into Blockchain.info. Transactions cannot be done without a valid signature using the private key that corresponds to the address you are sending the funds from. Where did you get the address from? Do you still have the private key? A private key should start with either 5, K or L.