Embed Code Global Embed won’t clear text area

Hi,
I have downloaded Embed Code to insert a donation form plugin. By mistake, I first put the embed code in the settings area of the plugin’s head tag that puts in globally on the site. I only want the code to appear on a specific page. I went back to settings and deleted the code and saved changes. The code reappears. I have tried deactivating and uninstalling the plugin. Re-installing and activating makes the same code appear in the global head tag even though I did not put it back in. it’s forcing me to have something in that code box. The code was replaced with a / but that shows on my website page. How do I leave this area blank and only have the code appear on my page by pasting code on the embed code field on that page.