Module development and code questions

hello,

I have a paragraph text field where user will enter text.  In between some headers, I want to insert a variable that is created in the subtheme file.  For example, in the paragraph there is :

 Header

paragraphs

{{ my variable }} - I want to put this anywhere within the text.

More text

Initially, I had the variable placed at the end of the paragraph, but I realized that the users will want to place the variable anywhere they want inside the paragraph.

My Drupal 10 website hosted on OVH was functioning normally and everything was working fine.

However now when I try to access any page containing a form, it displays this error, even though I haven't made any changes or modifications:

*The website encountered an unexpected error. Try again later. Drupal\Core\Database\DatabaseExceptionWrapper: SQLSTATE[42000]: Syntax error or access violation: 1142 INSERT command denied to user 'xxxxxxx'@'xx.xx.xx.xx' for table 'watchdog': INSERT INTO "watchdog" ...

I'm building a custom module which calls for a table that has TH tags as the first cell in every row of a table.  Be damned if I can figure out  how to make that happen.

<!--break-->

The table.html.twig documentation says:

Each cell contains the following keys:

I have created custom module to load records dynamically with Ajax callback in custom block in drupal 10.2. But Ajax callback does not work in custom block, where callback function is written on same custom block file, please see the code below,

Dear Drupal Support Team,

I recently deployed my Drupal 10 website on OVH, making it accessible to the public. However, when I test the form (Webform module) which includes a field for uploading a file, upon clicking the 'submit' button, an error appears on the page: Error 503 Backend fetch failed. Guru Meditation: XID: xxxx Varnish cache server.

The form is a 'Webform' module in Drupal 10. It was working correctly in my local environment; I was able to submit the file without any issues. However, now that it's in production, when I test it, I encounter this error