Protecting btc wallet

Question for protecting btc wallet

Hello! Im planing on using multisig for a btc wallet. This multisig works with a 2of2 model where I hold my keys and the rest of the keys are in blockstream serves. When I want to back up or move funds I needs to use my keys and the 2fa from blockstream. So here is the question related to hacking. I have the option of using call, sms, email or authenticatior app. If I’m protecting myself against spyware/malware which one of those options would be the safest? Many thanks !