odoo16/addons/l10n_ec/views/account_tax_view.xml

<?xml version="1.0" encoding="UTF-8"?>
<odoo>
    <record id="account_tax_form_view" model="ir.ui.view">
        <field name="name">account.tax.form</field>
        <field name="model">account.tax</field>
        <field name="type">form</field>
        <field name="inherit_id" ref="account.view_tax_form"/>
        <field name="arch" type="xml">
            <xpath expr="//field[@name='type_tax_use']" position="after">
                <field name="l10n_ec_code_base" attrs="{'invisible': [('country_code', '!=', 'EC')]}"
                       groups="base.group_no_one"/>
                <field name="l10n_ec_code_applied" attrs="{'invisible': [('country_code', '!=', 'EC')]}"
                       groups="base.group_no_one"/>
                <field name="l10n_ec_code_ats" attrs="{'invisible': [('country_code', '!=', 'EC')]}"/>
            </xpath>
        </field>
    </record>
</odoo>