Adding buttons to Add New Post and Add New Page

Question

I want to add a button in Add New Page and Add New Post pages.

Here are places I want to add items:

• New page's sidebar (next to Page Attributes).

• New post's sidebar (next to Post Attributes).

• New page's top bar (next to Block Navigation).

• New post's sidebar (next to Block Navigation).

What are the action hook to do it so?

function add_new_button_function (???)
{
    echo "some html code";
}

add_action( '???', 'add_new_button_function' );

Answer 1

Welcome!

Here is a documentation for adding Custom sidebar. You can check possibilities and sample codes to add new metaboxes or buttons.