Hello Mert,
Hope all is well with you.
I'm looking to do a post that includes some custom javascript functions. I've looked over the documentation but found no information about this there. I read (https://www.wpbeginner.com/wp-tutorials/how-to-easily-add-javascript-in-wordpress-pages-or-posts/ ) that adding a custom field could be a way to do this. But placing the {{CODEmyjscode}} in the editor does not do the trick. Any suggestions on how I can achieve this?