Drupal 8.x

Hello, first of all thanks to ready my post in "Low English", sorry but it is not my native language.

I am not developer, i am systems technician but in my job we have changed from WIX to DRUPAL and i have migrate all content (published content, not configured the core site) WIX was totally family friendly, i had a editor to the content in mobile devices and another to the computers.

Once I updated a page via admin panel, I need to programatically flush all the caches, then get the page source code and write it to a file. I use the following code inside of my module:

Hi

I'm using headless Drupal via rest API.

i want to create a link that when user open it the user was authenticated to continue purchase a product .

can some one help me?

Hey there. I have some functionality I am working on that relies on Ajax. I have an entity autocomplete that runs the autocompleteclose callback when you select an item from the dropdown list. 

When you do this, if a specific entity type is selected from the list, it adds an additional field to the form. I also have repeatable fields (add/remove another) that runs additional ajax. 

When just doing one item, this works, but once you rebuild the form, the additional field doesn't show up, even if the autocomplete box has the required item. 

How to add font awesome icon on textfield left side "as per" input type for example

username textfiled appear user font icon

mobile textfiled appear mobile icon

please suggest any module for this.

I also share accept output 

image link https://i.stack.imgur.com/MDMMm.png

please help us

Thank you

drupal 8.9.17

I am looking into updateing to drupal 9.x from 8.9.17 so I installed upgrade status. 

And i have the following message. 

looking at drupal/sites/default/settings.php I am not seeing anything to change.