RSS widget with nofollow

I’m looking for a RSS widget to promote my site on other blogs. To avoid a penalty, I need the links to have ‘nofollow’ attribute. Because the widget will be used on sites managed by other people, it needs to be as simple as a checkbox. The widget will need to show the title, image would be a plus.

Example of a similar widget (lacking the nofollow): https://www.spitsnieuws.nl/ bottom right (desktop view) under Kortingscode

Hoping you can point me in the right direction.