How to call a block inside a view page?
Here is some possible ways to do it: 

1. using no extra modules

Click ADD next to header or footer area and look for GLOBAL: Rendered entity - Block.  The configuration asks for view mode and block id

 

2.  using  Views block area module

You can use Views block area module that will allow you to insert a block as a field or in header or footer area.

3.  using preprocess / twig

if you want to add the block using your twig template in your THEMENAME.theme file using a preprocess function 

function THEMENAME_preprocess_XXX (&amp;$variables) {
    $block = \Drupal\block\Entity\Block::load('id_block');
    $variables['myBlock'] = \Drupal::entityTypeManager()
        -&gt;getViewBuilder('block')
        -&gt;view($block);
}


and then inside your twig file use this  

{{ myBlock }}


To find appropriate preprocess function look in your twig file comments. 

For example if you want to use views-view--unformatted.html.twig you can see in the comments  

* @see template_preprocess_views_view_unformatted()


which means include in your .theme file THEMENAME_preprocess_views_view_unformatted() function