​Hello esperanza,

Using OWL Framework, you can easily inherit Components, Models, and Templates in PoS.

How to inherit PoS Components:

/** @odoo-module */

import Registries from "point_of_sale.Registries"
import ProductScreen from "point_of_sale.ProductScreen"

const ProductScreenInherit = (product_screen) => class extends product_screen {
​ ​setup(){
​ ​ ​super.setup()
​ ​ ​ ​//... your code
​ ​}
}

How to inherit PoS Models:

/** @odoo-module */

import Registries from "point_of_sale.Registries"
import { PosGlobalState } from "point_of_sale.models"

const PosGlobalStateInherit = (models) => class extends models {
​constructor(obj) {
​ ​super(obj);
​ ​ ​ ​//... your code
​}
}

Registries.Model.extend(PosGlobalState, PosGlobalStateInherit)

How to Inherit PoS Templates:

xml version="1.0" encoding="UTF-8" ?>
<templates id="template" xml:space="preserve">

<t t-inherit="point_of_sale.ProductScreen" t-inherit-mode="extension" owl="1">
​<xpath expr="//div[hasclass('rightpane')]" position="inside">
​ ​//... your code

To learn more, kindly check this video below:

https://www.youtube.com/watch?v=zQ_iHwpg0Pg