I am trying to send a mail to the portal user who've successfully submitted a request and I'm getting this error KeyError: False.

These are my controller and template codes. 

@http.route('/submit', method='post', type='http', auth='public', website=True, csrf=False)
def send_request(self, **post):

    values = {
        'name': post['subject'],
        'maintenance_team_id': post['teams'],
        'equipment_id': post['equipment'],
        'description': post['details'],
        'priority': post['stars'],

    }

    print(values)
    # maintenance_request = self.env['maintenance.request'].search()
    request.env['maintenance.request'].sudo().create(values)
    search_ids = request.env['maintenance.request'].search([])
    last_id = search_ids and max(search_ids)
    print(last_id.id)
    template = request.env.ref('website_maintenance.mail_template_maintenance_request')
    print(template)    
    template.send_mail(last_id.id, force_send=True)
    return redirect('/maintenance_request-thanks')

template

<odoo>
    <data>
         <record id="mail_template_maintenance_request" model="mail.template">
            <field name="name">Maintenance: Reception Acknowledgment</field>
<!--            <field name="model_id" ref="website_maintenance"/>-->
            <field name="subject">Maintenance request received</field>
            <field name="email_to">robodoo2019@gmail.com</field>
            <field name="body_html"><![CDATA[
                <div>
<!-- Just trying to send an empty mail first -->
                </div>]]>
            </field>
        </record>
    </data>
</odoo>

What am I doing wrong here?