in odoo12
pos-->setting-->POS (Name)It's displayed on the checkout screen.
file:odoo\addons\point_of_sale\static\src\xml\pos.xml
<?xml version="1.0" encoding="UTF-8"?>
<templates id="template" xml:space="preserve">
<t t-name="Chrome">
<div class="pos">
<div class="pos-topheader">
<div class="pos-branding">
<img class="pos-logo" src="/point_of_sale/static/src/img/logo.png" alt="Logo"/>
<!-- display the name of pos -->
How to display the name of pos in use