There's only 3 options (I'm on the panel), Google Prompt (requires a phone), security key, or text message/voice call (requires a phone). 2 out of 3 require you

There's only 3 options (I'm on the panel), Google Prompt (requires a phone), security key, or text message/voice call (requires a phone). 2 out of 3 require you to attach a phone number and the last one requires a security key to be inserted every time you want to make throw away accounts via Gmail.