Add selection box in custom pages

I have some questions about custom pages like pos pages. and i want to add selection box in my custom pages. how to add the selection box inside js files in my custom pages.

here’s something i want to try but im stuck and idk how to make that text box become selection box
and thanks if somebody can help me about that :slight_smile:

open the doctype and from menu choose customize and change the field type of the field you want to select and enter the options you wanna choose from

Thanks for the replay @Mohammed_ElKadee
but its custom pages and its not doctype. thats why idk how to custom the input text in that html page,
for now i think ill use my custom web for pos and integrate it with erpnext using REST API from erpnext