flectra/addons/sms/views/res_partner_views.xml

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

    <!-- Add action entry in the Action Menu for Partners -->
    <record id="partner_form_send_sms_form_view" model="ir.ui.view">
        <field name="name">res.partner.form.send.sms</field>
        <field name="model">res.partner</field>
        <field name="inherit_id" ref="base.view_partner_form"/>
        <field name="priority">10</field>
        <field name="arch" type="xml">
            <xpath expr="//field[@name='phone']" position="replace">
                <label for="phone"/>
                <div class="o_row">
                    <field name="phone" widget="phone"/>
                    <button
                        type="action"
                        name="%(sms.send_sms_form_action)d"
                        class="btn-xs btn-link mb4 fa fa-envelope-o"
                        attrs="{'invisible':[('phone', '=', False)]}"
                        context="{'field_name': 'phone'}"
                    />
                </div>
            </xpath>
            <xpath expr="//field[@name='mobile']" position="replace">
                <label for="mobile"/>
                <div class="o_row">
                    <field name="mobile" widget="phone"/>
                    <button
                        type="action"
                        name="%(sms.send_sms_form_action)d"
                        class="btn-xs btn-link mb4 fa fa-envelope-o"
                        attrs="{'invisible':[('mobile', '=', False)]}"
                        context="{'field_name': 'mobile'}"
                        />
                    </div>
                </xpath>
        </field>
    </record>

</flectra>