No, that is not correct.
A button in the template will work.
If you were trying it before in a form where form_tag = True, then the issue would most likely have been that the button was being rendered outside the <form ...> element.
In this situation, since you are rendering the <form ...> and </form> elements, you can ensure that the button resides within that element.
Or, if you want to ensure the button is part of the layout, you can include the submit button in only one of the forms. A submit button will submit all fields within the <form> element, regardless of how many Django forms are rendered within that element.
(Don’t lose site of the principle that a Django form is not the same thing as an HTML form - they exist in two different physical locations and have two completely separate sets of properties and behaviors.)