plupload doesn't work

Hello, I try to write here, please let me now if it's the right place.
I've a strange problem: I've installed plupload module+plupload library in my Drupal10 server and I've written this php code to use plupload:

$form['fileimporta'] = array(
'#type' => 'plupload',
'#title' => t('Scegli i files XML (il nome del file non deve contenere spazi o caratteri speciali). Massimo 10.'),
'#upload_validators' => array("file_validate_extensions" => array("xml XML")),
'#plupload_settings'=> array(
'runtimes' => 'html5',
'unique_names' => TRUE,
),
'#required' => TRUE,
);

when I try to understand what's in my 'fileimporta' field with
$form_state->getUserInput()['fileimporta'])
or $form_state->getvalue('fileimporta')
the result is NULL.
In Drupal 7 works, of course.
Any ideas?
THANK YOU!
Renata.

No,

Hello,
I've used your test module but still doesn't work, even the field 'upload' in the validate part of code is empty.
I think I've something wrong in my Drupal10 installation but I don't understand what...
It's very strange 'cause I've got NO errors...
Thank you for any advice.
Renata.

If I had to debug your issue I would try the following:

1. Visit /admin/reports/status and check there are no messages in the "Plupload library" section. Something like "2.3.9" should appear.
2. Visit /admin/reports/dblog and ensure there are no messages related to writing files nor file system.
3. Access the plupload test page at /plupload-test and try to upload a very small file.
4. Instead of pressing directly the "Submit" button, click "Start upload" first, ensure a green tick appears at the right, and then "Submit".
5. Also you can check browser console for messages when clicking "Start upload".

6. If files are empty in the validate function, probably you don't have correct permissions at temporary directory or public files directory but definitely some message should appear at "Recent log messages" at this point.

Hello budalokko and thank you so much!
From your png I've noticed that "stop" and "done" gif in my Drupal didn't appear (I don't know why...).
At the same time my collegue had a problem in the same Drupal installation with Javascripts so we decided to update Drupal 10.0 to 10.1.4 and... now correct gifs appear and, more important, $form_state->getvalue('fileimporta') is no more null.
Now i'm trying getting file-id of these uploaded files (with Drupal7 I've used this method: https://drupal.stackexchange.com/questions/108583/how-to-save-file-uploa... but now it doent's work, of course). Any suggestions?
Thank you!
Renata.

No news from the original reporter for years so closing as outdated.

@RenataBin if your issue is still not fixed, you could create new support request with detailed information on what you did and what errors you get.