Can someone tell me how to create a signup and login page for blogger and put them in the header

Question

I use jotform to create some sort of sign up page which is located at the side bar of my blogspot blog. I get the information and either add the person as a contributor or administrator. they are then sent an invitation link by Google. But now I I want to put sign up in header by link reference.

Answer 1

Do you know this for Coding Q/A ?
“Not for blogger”

Answer 2

I know . but is there no way I can use what I've learnt here for different platforms . at least for now before actually building my own website . but can't let go of my blog .