How to set custom donate button in the Fundraising plugin settings?

Hi there -

There's an option within the settings of the Fundraising plugin that implies we can customize the "donate" button. However, I'm not seeing where I can either upload a custom image or designate a link to the image.

I looked through the plugin documentation and haven't found the info there, either.

Am I missing something? The site I'm working on is on my local server, so I'm not able to provide access at this time.

Thanks in advance for your help!
Cynthia