How to add custom field like batch_no in pos.js?

i have some questions about POS, i have tried to do in this topic Custom Fields in POS, but it seems it doesn’t work for me, can somebody help me ?

POS is a page, not a DocType so there is no such provision to add Custom Field in it.
For adding fields in it you have to modify existing pos HTML and js files. for that, you can refer mentioned thread. But making changes in erpnext/frappe files is not recommended.

There is also one way to extend page functionality,

check - Extending DataImportTool class from javascript - #8 by JoEz

yes i know POS is a page and i already try to modified it in pos.html and pos.js files but im stuck in there.
so i was try making new custom page like POS page but i cant find my custom page html files and js files too. did i need to make new html and js files by myself ? or there’s another way ?
and thanks for your replay @Sangram

js file gets auto-created after page creation. check it under the selected module. HTML you have to create manually.

ohh… ok ill try making my custom html and how to load my custom html ? did i need to add something in another files ?

refer pos.js file.

use frappe.render_template("html_file_name") to load your html in it

oh… i see ok ill try that too, thanks @Sangram

hello @Sangram i already try what u told me before and its work but i get new trouble here, i want to change the input text into select option in my custom page js. and how to do that ?

this is what i want to change into select

continues here Add selection box in custom pages