You can configure it manually from general settings then from companies settings click on configure document layout and in the footer set your details you want to show as below:

+1 (650) 555-0111 info@yourcompany.com http://www.example.com vat:123456 

If you want to show the info automatically from company and for example you are using standard layout you will inherit web.external_layout_standard to add website, email, vat,..etc

<template id="external_layout_standard" inherit_id="external_layout_standard">
    <xpath expr="//div[contains(@t-attf-class, 'footer')]/div/ul" position="before">
        <ul class="list-inline mb4">
            <!-- using the list-inline-item class from bootstrap causes weird behaviours in pdf report
                 adding d-inline class fixes the problem-->
            <li t-if="company.phone" class="list-inline-item d-inline">Phone:
                <span class="o_force_ltr" t-field="company.phone"/>
            </li>
            <li t-if="company.email" class="list-inline-item d-inline">Email:
                <span t-field="company.email"/>
            </li>
            <li t-if="company.website" class="list-inline-item d-inline">Web:
                <span t-field="company.website"/>
            </li>
            <li t-if="company.vat" class="list-inline-item d-inline"><t
                    t-esc="company.country_id.vat_label or 'Tax ID'"/>:
                <span t-field="company.vat"/>
            </li>
        </ul>
    </xpath>
</template>