post with js and php

Hello @harrymk,

https://www.wpbeginner.com/wp-tutorials/how-to-easily-add-javascript-in-wordpress-pages-or-posts/

hello @aminulsiam.
thank you for your help.
however, I only wish to add javascript and php together into the post manually, which means I will add in every posts I want, with which may or may not be the same codes for every manual posts.