I created a custom content type that its name is News and has an image field with news_image machanic name and I added an
alternative text to it from administration page,
now I want to print that alternative text when the node content type twig template rendered.
what I want to achieve finally is schematically something like below:
<img src="#" title="#" alt="Alternative text">
It seems this problem can be traced back to custom content type only because alternative text can be printed without any problem in default content type like article.