Hello Mel,
Currently, when adding a Donation Campaign from the frontend, Joom Donation does not display the category dropdown select list. This feature will be available in the next version of Joom Donation.
However, if you need it right now, please feel free to contact me directly via the Support ticket system. I’ll be happy to send you the development version of Joom Donation that already includes the category dropdown in the "Add Campaign" page.
Let me know if you’d like to receive it.
Best regards,
Dam