fetchmail_server_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
    <record id="fetchmail_server_view_form" model="ir.ui.view">
        <field name="name">fetchmail.server.view.form.inherit.gmail</field>
        <field name="model">fetchmail.server</field>
        <field name="priority">100</field>
        <field name="inherit_id" ref="fetchmail.view_email_server_form"/>
        <field name="arch" type="xml">
            <field name="user" position="after">
                <field string="Authorization Code" name="google_gmail_authorization_code" password="True"
                    attrs="{'required': [('server_type', '=', 'gmail')], 'invisible': [('server_type', '!=', 'gmail')], 'readonly': [('state', '=', 'done')]}"
                    style="word-break: break-word;"/>
                <field name="google_gmail_uri"
                    class="fa fa-arrow-right oe_edit_only"
                    widget="url"
                    text=" Get an Authorization Code"
                    attrs="{'invisible': ['|', ('server_type', '!=', 'gmail'), ('google_gmail_uri', '=', False)]}"
                    nolabel="1"/>
                <div class="alert alert-warning" role="alert"
                    attrs="{'invisible': ['|', ('server_type', '!=', 'gmail'), ('google_gmail_uri', '!=', False)]}">
                    Setup your Gmail API credentials to link a Gmail account.
                </div>
            </field>
            <field name="password" position="attributes">
                <attribute name="attrs">
                    {'required' : [('server_type', '!=', 'local'), ('server_type', '!=', 'gmail'), ('password', '!=', False)], 'invisible' : [('server_type', '=', 'gmail')]}
                </attribute>
            </field>
        </field>
    </record>
</odoo>