Is there a way to switch the form I created in multi-page by mistake to a single page?

Is there a way to switch the form I created in multi-page by mistake to a single page?

I think you are looking at converting Card forms into Classic forms, right?

If that is the case, you can change the "Form layout" from Settings > Form Settings > Show more options. Scroll down to the "Form Layout" section and change the option to "All questions in one page" as shown below.