yesterday I found a backup on my computer so I remembered the password I access the account with the private key etc except that the problem is with Google authenticator and in the meantime I changed my phone so I no longer have the QR code recorded
Your wallet is a 2FA wallet with Electrum. With 2FA wallet, if you use it, you will need 2FA code, that will also cost you more in transaction fee.
Fortunately, there is a way out, if you no longer want to use 2FA feature, you can import that wallet mnemonic seed, and disable 2FA. After importing it, you will have a same wallet with same public addresses, you can check it yourself, and you can spend your bitcoin without 2FA from Trusted coin.
Do it like this.
Create a wallet.
Wallet with two-factor authentication.
I already have a seed.
Next.
You will see "Restore 2FA wallet" with 2 options: Keep or Disable.
Disable if you no longer want to use it as a 2FA wallet.
Next.
Type te wallet password and finish.
I just contacted them, I'm waiting for them to answer me before sending my private key and the backup? Is that preferable?
No. It's your private key, it's your bitcoin. It's your back up, it's your bitcoin. If you send them to anyone, including Trustedcoin, you will lose that wallet and any bitcoin in that wallet as well.