how to hide header on the post entry?

Hey Salva,

With Generate Disable Elements addon or GP Premium you can achieve that on each post by selecting Header option.

Check this page for more information: https://generatepress.com/downloads/generate-disable-elements/

Hope I've helped. :)

Ok thank!

If you want to apply that to all of posts and not check them individually, try this CSS:

.single-post .site-header {
    display: none;
}

Adding CSS: https://docs.generatepress.com/article/adding-css/

Hope this helps!