Twig Components / Methods / form_start

form_start(form_view, variables) is a Twig function to render the start tag of a form. This helper takes care of printing the configured method and target action of the form. It will also include the correct enctype property if the form contains upload fields.

{# render the start tag and change the submission method #}
{{ form_start(form, {'method': 'GET'}) }}

Source: Forms