Module development and code questions

Hi,

After reading a lot of posts, testing with postman several things I still can't figure out
how to use the REST API for creating content and more generally how to use the core REST API.

Where I am until now

I'm just trying to create a simple page as a starting point.

In the header section of POSTMAN :

'Content-Type': 'application/hal+json',
'X-CSRF-Token': 'MYTOKEN FROM /session/token',
'Accept': 'application/hal+json',

In the body section of POSTMAN :

The use-case is a brochure website with means to contact some people.

The only person that shall be able to log in is the content editor.

I want to enable a personal Drupal contact form for each department head.

I've created user accounts for all department heads.

However, they shall not be able to log in, or to request a password reset.  Therefore, I've set their status to "Blocked".

I have a remote video Media Type and it's set up with CKeditor. 

When I add a video media entity there is an "edit media" button attached to the video in the editor. 

Clicking this button gives me options that are not useful for video for us: alignment and caption.

How can I remove the Edit Media button from videos added with media to CKeditor?

Hello everyone

I am PHP Developer who is getting into Drupal (we had a need for CMS and Drupal gets best reputation among other Devs who I know so after brief research we decided to go with it). 

Currently investigating issues with upgrading D8.9.20 to D9. Running into a removal of drupal/ctools_block 3.4.0 while drupal/ctools 3.7.0.

For the record drupal/ctools_block is a submodule of drupal/ctools. Should the composer.json have replace/provide sections for its submodules?

Looked for documentation, couldn't find it, anyone knows where this is documented?

I have configured 2-factor authentication using TFA module. All the configurations seems correct but when I login to the site, I don't get redirected to TFA code request  page. In the network tab under the "Response Headers" section I see the location as: