Here's how;

Go to App>Create Till app codes and then extend the number of records to display, bottom right;

Then flood fill the names above the first name at the top and continue to page 2 and 3 as necessary to add all the names to the white box, top right of the names display you wish to generate a code for;

When you have ticked all the names you would like to generate an App code for, click> Create Till App Code;

Confirm here;

Then go to>Manage Till App Codes to generate a csv;

You can generate csv of current, 'live' codes from the bottom of this page, save to your PC and then filter and use this csv as required in your communications out to users/parents.