Scramble

After entering OpenAI API key, extension still says "API Key Not Set"

I created an OpenAI API key with full permissions, clicked on the extension and then clicked "Open options", pasted in the API key and clicked Save. It did pop up a "saved" toast, but nothing else appears to have happened and the extension still says "API key not set" and displays the button to open options. There are no errors when I try to use it (right-click on text, select Scramble and "improve writing", for example, but it also doesn't do anything else.