Module development and code questions

I'm trying to change the text of the "Login failed" flood control page. I can do that but I lose Drupal's maintenance page theme. I get nothing but my new message text. This is what I did:

bncreports.module

I have created a new module for dupal and would like to contribute to the community. The problem is that I don't know how to create the composer command to install the module.

Have someone a tutorial?

Thanks in advance.

Hello. Can someone tell me a possibility or way to work and use the "form mode" of the entities, in drupal 9, the examples for drupal 8 no longer work with drupal 9. Code to use it in a custom module. I need to use them with a conditionality: user, field etc. I need the correct hook and the way to use it. Thanks.

Hi all.

I have my custom entity created from the admin's Drupal 9 interface that also references to other custom entities.

For our decoupled front end, I am developing a module that adds custom resources to the core Rest Api (get, patch, and post):

How to embed Looker in drupal website so users can embed dynamic data tiles as content though iFrames.

Hi,

I am trying to update the metatag robots from "robots" to "index, follow" on nodes. But it is not updating for existing as well as new nodes. It's being reset to "robots" after saving the node.

Indeed the global configurations are already set to "index, follow". Why is this behaviour happening?