There is a field for a preferred name. Once you update it, it should mirror into all systems after a couple of days.

Your initials and email address will not update, this probably requires a legal name change and contacting the student administration desk or your academic advisor.

3rd party services using the RUG SSO login (like ACLO) may still display your deadname!

This can probably be changed only by changing your name legally and informing the dutch government, it should then automatically sync with the university.