Best way I solved this, inside the form:
<%= hidden_field_tag :authenticity_token, form_authenticity_token %>
Update:
It looks like the form_authenticity_token is private for controllers in the newer rails versions.
If that’s the case for you, what I suggest is: declare a variable in a controller like:
@form_token = form_authenticity_token
and use it in the view you are looking for.