Sendgrid's only options for 2FA are Authy (their proprietary token generation, no option for TOTP) or SMS. Tried signing up the other day and was surprised to find no option to use standard TOTP.
https://docs.sendgrid.com/ui/account-and-settings/two-factor-authentication
Yes I'm sure, hence why I specifically mentioned that. Try the sign up procedure yourself. It REQUIRES 2fa and it has to be Authy's non-standard token or SMS. No option for regular TOTP.