Found another solution to this.

<?xml version="1.0" encoding="utf-8"?>

<odoo>

<record id="custom" model="ir.ui.view">

<field name="name">Custom Page</field>

<field name="type">qweb</field>

<field name="inherit_id" search="[('website_id', '=', 1), ('key', '=', 'website.homepage')]"/>

<field name="key">website.homepage.custom</field>

<field name="website_id" eval="1" />

<field name="arch" type="xml">

Add your custom code.

</field>

</record>

</odoo>

In case you don't wanna use website id then use

<field name="website_id" search="[('name', '=', 'Second Website')]"/>

same can be replaced in inherit id parameter as. Instead of website_id you can use website_id.name and pass the website name

This will help inherit any website template. Once your inheritance is successful you should an external id generate(Provide the code is not inside website module)

Tested above code with theme_clarico_vega.

Please mark the answer as correct. If it works for you.

It will help others

Hello Yurii,

Thanks you for information. I have tried the same.

How we can define website_id when I am using theme for multi website. As Example below,

I have three websites 1) website1 2) website2 3) website3 and I am using theme_test in the webiste1 and website3

So which website_id I need to provide in the below code.

<template id="layout" name="Main layout" inherit_id="website.layout" website_id="website.default_website">

Also we have applied website on view as you can check on below screenshot still not create external id

(screenshot https://nimbusweb.me/nimbus-screenshots/64531b78ad42d13e6f6f7655290c3aa3)

So as now, if we need to create/generate external identifier for multi website, as external id have unique constrain, so can you please elaborate more how we can generate external id based on each website view with the unique constrain?