Hi,
I also wondered about it and emailed the student services and got the following reply:
Good morning,
We thank you for your email.
We have sent you your admission letter to EPFL for the academic year 2021-2022 on the 24.03.2021. There is no other admission letter.
You may print your enrolment certificate from your secure access once the semester has been paid as mentioned in our email sent to you on the 03.06.2021.
With our best regards.
That being said, I got my GASPAR account info on 02.06.
Hope this helps.