See the notes on their V2 docs page.
It'd be great to update the README for this repo to note this.
This drove me crazy today, and the official sendgrid node lib is ridiculously overengineered.. so if anyone else ends up here via searching around, I highly suggest using this module: https://github.com/adamreisnz/sendgrid-mailer It's not compatible with nodemailer unfortunately (seriously no idea what sendgrid is thinking....), but it's the simplest, usable solution to get up & running w/ sendgrid from nodejs 😞