How do I set a custom input format for a field? After using Drupal 7 for years, I am now handed a Drupal 8 site to do some editing. I have created a custom input format (Plain HTML), and I want to print this field with this input format in a custom template. How can I achieve this?

With {{ content.field_mapka_markery }}, it prints plain text. There is no choice to select my newly created input format in the Manage display settings. Why is that? In Drupal 7 there is always a new formatter,  but not so in Drupal 8.

I also tried {{ content.field_mapka_markery|raw }} or .value. |raw doesn't  work at all, and .value does the same as without it.
Managed to create a new field with "Text - Formatted - Long" as default, which allowed me to set up my custom text format. Why is that not possible for plain text field I am not sure.