for header part of web-site, grid system is easy or navbar is easy for the search engine to optimize while making with bootstrap? [closed]

When creating the header part for my site, using with Bootstrap 5, I am confused whether I can create the header part with the grid system or I can create it with the navbar or I can use display-flex. Which one is easier and simpler to create, edit and more responsive?

I tried to use bootstrap5 with navbar but I faced some problem so I am not sure if navbar should be used with header part or we can use with grid system or flex-display also?