Dynlist has better than 2FA. Use Google login rather than email login. Google OAuth has better security features (machine learning, location, ISP, confiorm on phone notification, 2fa, lots of good stuff). A hacker would need to get thru the Google 2FA to reset your password or login to your Dynalist. You can’t really disable the email login altogether without signing up for dynalist again and never making one, but you can generate a super secure password that you just forget and don’t save anywhere. Then just login or password reset via google 2FA.
I’d also advise you not use Google Oauth for the backups location - say a youtube moderator misreads a comment and bans you across all Alphabet properties, and your only dropbox login was Google OAuth, then you just lost your dynalist AND the backups.