Drupal 8.x

On the product I created a "tags" taxonomy terms field. I have created a hundred "tags".

My products use around 10 "tags".

I created a pageview of my products with an exposed filter criterion "tags".

My problem :

The filter displayed on the product page displays all the terms. I only want to display the terms used by my products. How to do this ?

I am building a form that contains two image buttons and an undo button. The user clicks one of the two image button's and then the images are suppose to update to new images, and they do this about 60 times before we submit the results. The user can select the undo button to undo their last selection and select another one. This form is also displayed in a modal. However, I'm having some strange behavior with the images updating when you click the image...

Here's my routes file:

Hello, 

I am trying to create a testimonial block using the bootstrap theme. Is there any built-in bootstrap testimonial block that I can use including css/javadcript/jquery? I found some here and started working on it here but I do not see any css/jquery/js to it. I guess it requires lot of styling. 

Please advise

We have a context where we have a traditional php website which uses 'files' session_handler and both the drupal-8.9 website and this other website needs to share session information.

With D8 the default session handler uses a database.

I would like to have the D8 site use the 'files' session_handler to be able to share session information.

There seems to be two ways to do this:

1) ini_set('session.save_handler', 'files');

2) $sessionStorage = new NativeSessionStorage([], new NativeFileSessionHandler());

Drupal 8.8.5

In form_alter I insert this code to assign a default value to an Entity reference field
$form['field_localita_partenza']['widget'][0]['target_id']['#default_value'] = 'ROME';

During the insertion phase, I change Rome In Milan but when I save it forces me to value ROME and not MILAN.
I have done various tests but without success.
I don't understand why it doesn't work