There are several widget visibility plugins, like this: https://projectdmc.org/plugins/widget-options/
But for a single link, this would be like killing a wasp with a machine gun.
I would use a single line of custom CSS code to make the link visible on the homepage only. (If you want this code, you need to mention the specific widget.)
Thanks, but my problem is solved. I used Widget Options and limited the widget’s display to the home page.