How do I edit an already completed form?

I have created a form I have published it and tested it. It has a flaw. I can not figure out how to ed it it without recreating a new form  This is the third time. why Cant I access the already created form?

You can edit your form in the form builder page. You can access your form's builder page by clicking "Edit Form" in the MyForms page.

I hope this helps. If, in any case, I have misunderstood your concern, please do let us know and give us more details so we can assist you further. Thank you.