Datepicker on web page

How do I show a datepicker field in a web page? The outiside desk web page not inside.
I can’t find any example.
We have datepickers in web forms but can’t find on web page

do you mean html files in www/
you can use any js datepicker library and and collect the data from the form and send it to api you have written in python file if it’s a custom logic .

You can take a look at the book appointment folder ( erpnext > www > book-appointment folder) and you will find an example of how to do it