If you're having issues with the sign up link automatically opening in a non-Chrome browser, these quick steps will get you up and running in no time!
Open your email and find the Truly invitation.
Right click on the 'Sign Up' button
Click 'copy link address'
Open Google Chrome
Select the address in the address bar if there is one there and delete it
'Paste' the copied link and click enter
Click sign up via your email provider: Google, O365, or Truly (all other providers).