Module development and code questions

Good evening I would like to know if there is any way to add the shipping information to the invoice and to the notification email in Commerce 2

I am trying to save datecriteriamet date field to the backend and below is my function:

Developing a new school site using Drupal 9 and have been asked to secure a portion of the site to login only access.  Since Drupal is not using folder structure, how to secure certain nodes to password only.  Some modules available are not for D9 and not functional.  Idea would be to have a "Faculty Section" password only using our university AD id/passwords to gain access. Any suggestions?

Hi all

I have a module in D7 that I'm trying to change for D8.
It uses a hook form_alter to fo various things after a particular form is submitted.

I'm struggling to find how I get the submission status in the hook.
So has the form been submitted?

In D7 I used if(isset($form_state['input']['submitted']))

What is the syntax in a hook to check if a form has been submitted? I can't find an example anywhere.

Hi,

I'm trying to POST a simple file using HTTPClient (Rest API).
I have installed RestUi and configure everyting correctly (I can GET and POST any content type).

My problem is posting a FILE...
I have added FILE (with POST method) in RestUI.

When I launch my POST request, I get "403 forbidden" : 
"Client error: `POST http://XXX/entity/file?_format=hal_json` resulted in a `403 Forbidden` response: {"message":""}"

Hello I hope you can help me my page does not load the new slides that I add and I do not know what it may be, I hope you can help me then I add screenshots.

Drupal 7.6