I created a report with a table that has columns with the name, in the XML the name is in english but I would like to translate them into other languages, at the moment I tried with Italian but they remain in English. Column names are not the name of any model field. To create the report I took the odoo addons as an example, then to create the cycle report on docs by passing it partner_id.lang when I call the template.

imgpaste.net/image/oUuIz

call the report with docs loop

<template id="report_certificate">
    <t t-call="web.html_container">
        <t t-foreach="docs" t-as="o">
            <t t-set="lang" t-value="o.partner_id.lang"/>
            <t t-call="ngo_payment_certificate.report_certificate_view" t-lang="lang"/>
        </t>
    </t>
</template>

<template id="report_certificate_view">
    <t t-set="o" t-value="o.with_context(lang=lang)" />
    <t t-call="web.external_layout">
                   <t t-set="address">
                <address t-field="o.partner_id" t-options='{"widget": "contact", "fields": ["address", "name"], "no_marker": True}' />
            <div t-if="o.partner_id.vat" class="mt16"><t t-esc="d.company_id.country_id.vat_label or 'Tax ID'"/>: <span t-field="o.partner_id.vat"/></div>
        </t>
        <div class="page">
            <p t-esc="lang"></p>
                <h3 class="text-left mt16">Donations</h3>
        </div>
    </t>
</template>

I created the po file and added it to the addon by correctly translating the words. I reloaded the language by overwriting and restarted the server but nothing. He does not translate words for me.

Can you help me? After much research I was unable to find a solution. The rest of the addon, form, treeview etc, are translated correctly

I use Odoo 12 CE Odoo 12.0-20200121