How to integrate Flutter Web into a existing website without using a iframme

I currently have a working Flutter web application developed, and I want to add it between the header and the footer of my web page but the only way I can manage to do it is adding the Flutter web compilation as a external web and then referring to it as a Iframme.

Because it’s an iframme it does what iframmes do and screw up things like scrolling, real time height adjustments… etc.

I really found myself into a pickle in this one there’s supposedly a way but nobody not shown how.

Thank you in advance.