Module development and code questions

Whether I put it in page.html.twig or writing a preprocess function, 

<link rel="preload" media="(max-width: 576px)" href="/themes/custom/mytheme/images/header-576.webp" as="image">

gets removed completely from the page source.

Only when I remove the as="image" the line is, of course without it, in the page source.

I have two content types (User and Company). 

Content Type Info Image

I want to create a filter that allows users to search by company name. Currently, the company field is a text field, but I want to list all companies as checkboxes.

Is there a way to do this in Drupal 10?

I am running a Drupal site since Drupal 4 days.............It got upgraded from Drupal 7 to 8 successfully and now it is running Drupal 10.

Before Drupal 8 I was having a block showing recent comments as table with 1. comment subject, 2. author, 3, node title and 4 date-time as fields. I had put code to change the node title to an alternate title (say title_mf which I have in a different table with additional/alternate data for nodes ... node_alt_data)

Hi all !!!

Hello good!

I need help with a problem that we have detected on the website of one of our clients (escofet.com). 

We have seen that there is spam code injected into static pages, but I can't find how it gets there. It does not appear in the database, nor in any ftp file... 

I have deleted the content of the page template and it continues to appear.

In the home page, for example, the following code appears, which is only visible in the source code:

Hi,

I have created a website for a food bank that generates food vouchers by identified referrers. The food voucher code is exchanged for food parcels by the person referred. All works perfectly well but I need to display statistics about the food parcels on the website.