You can obtain your share code from the Government website: https://www.gov.uk/view-prove-immigration-status
To log in you will need:
details of the identity document you use to sign in to your UKVI account (your passport, national identity card, or biometric residence card or permit)
your date of birth
access to the mobile number or email address you used to sign in to your UKVI account - you’ll be sent a code for logging in
To generate a Right to Study Share Code, you need to select the option “To prove my immigration status for anything else” when asked why you need a share code. Do not choose any other options, such as work or rent, as these codes will not work for this purpose.
Option three (“To prove my immigration status for anything else”) is the only Share Code that the Student Immigration Team can access, which is why we refer to it as a “Right to Study” Share Code.