Hello,
You need to set one column in the Theme Settings > Footer
Then create HTML block with two rows. One row is for the desktop, hide its column on mobile, insert an inner row, and build your footer for the desktop. The second row is for mobile configure it accordingly.
Then navigate to Appearance > Widgets add HTML block widget into the Footer column, and choose you HTML block.
Here are manuals and tutorials which would help you:
HTML blocks – https://xtemos.com/docs/woodmart/html-blocks-2/
Hiding columns – https://wpbakery.com/video-academy/control-elements-different-devices-responsive-column-controls/?v=9025a1ae8c64
Best Regards