odoo16/addons/website_blog/views/blog_post_add.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

<record id="blog_post_view_form_add" model="ir.ui.view">
    <field name="name">blog.post.view.form.add</field>
    <field name="model">blog.post</field>
    <field name="arch" type="xml">
        <form js_class="website_new_content_form">
            <group>
                <field name="website_url" invisible="1"/>
                <field name="blog_id" string="Select Blog"/>
                <field name="name" placeholder="Blog Post Title"/>
            </group>
        </form>
    </field>
</record>

<record id="blog_post_action_add" model="ir.actions.act_window">
    <field name="name">New Blog Post</field>
    <field name="res_model">blog.post</field>
    <field name="view_mode">form</field>
    <field name="target">new</field>
    <field name="view_id" ref="blog_post_view_form_add"/>
</record>

</odoo>