Create Drupal user from donation pages?
Seems you need to add a profile to the contribution page with Account creation required enabled.

To do this -


Check for the profile added to your contribution page on Profiles tab from Manage Contritbuion Pages or by visiting civicrm/admin/contribute/custom?action=update&amp;reset=1&amp;id=&lt;page_id&gt;
Navigate to Administer -> Customize Data and Screens -> Profiles.
Click on Settings link for the profile added to your contribution page (Create if no profile is added).
Open Advanced Settings tab and look for the Drupal user account registration option? input field.
Enable Account creation required and navigate to the contribution page to see the populated drupal username field.