Module development and code questions

I am new to OO PHP. I get this error message (I am trying to upgrade the Notify project to D9):

"Error: Call to undefined function Drupal\notify\Form\getCount() in Drupal\notify\Form\QueueForm->buildForm() (line 156 of modules/contrib/notify/src/Form/QueueForm.php)"

The call is made from inside the public function buildForm that is in class QueueForm extends ConfigFormBase in a file named "QueueForm.php", and looks like this:

I'm working on a module that performs some tasks related to content translation at creation/edition of nodes.

I want to prevent some users to edit in particular languages. If current editing language is not the good one I would like to reload page with the appropriate language (i.e. send user to /node/edit/10 if he is on /LANG/node/edit/10).

Is it possible from within my HOOK_form_alter()? Returning a redirectResponse() have no effect (which is logical).

Is there any other way?

Thanks.

Using Olivero for a personal site, whenever I look at another option I always go back to Olivero. It has that something...

Someone knows if there is any option though, inside Drupal, where I can change the size of the tiny featured images? The only option I thought of was to edit theme code. But, asked this first, as there are a lot of settings on Drupal admin, to be shure. Thank you in advance.

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