I created a custom block "Share". This one is not displayed on any page.
I installed the "Twig Tweak" module.
How to display a custom block in a view ?
If you want to add it to the header or the footer, edit your view, and in the middle column next to header or footer click add and then select Rendered entity - Custom block
When adding the block, just use the block ID (that can be found in the block's URL - in the image you uploaded your block ID would be 103)
Make sure these options are checked / filled in.
