How do I add an anchor attribute to a route? I've created a route:

regions.taxonomy_term.edit_form_header:
  path: '/taxonomy/term/{taxonomy_term}/edit'
  defaults:
    _entity_form: 'taxonomy_term.default'
    _title: 'Edit term'
  options:
    _admin_route: TRUE
  requirements:
    _entity_access: 'taxonomy_term.update'
    taxonomy_term: \d+


But now I can't add to path anchor attribute.

For example:

path: '/taxonomy/term/{taxonomy_term}/edit#header'
Thanks everyone! 

I have solution my for problem.
You just had to add it to this my_module.links.contextual.yml file.

regions.taxonomy_term.edit_form_header:
  title: Edit this block
  group: region_taxonomy_term
  route_name: regions.taxonomy_term.edit_form_header
  weight: 10
  options:
    fragment: 'edit-group-header'