Allowed Formats

Limit which text formats are available for each field instance. You will find a set of checkboxes for the field settings (not the widget settings on the form display tab) of text fields.

Note that base fields defined by the entity type (for example the description field of taxonomy terms) cannot have their allowed formats limited through the UI.

If you use this module and would prefer if this functionality was built-in, please get involved in the original issue for Drupal core: #784672: Allow text field to enforce a specific text format