app/helpers/application_helper/button/miq_request_approval.rb
class ApplicationHelper::Button::MiqRequestApproval < ApplicationHelper::Button::MiqRequest
needs :@showtype, :@record, :@request_tab
def visible?
return false unless super
return false if %w[approved denied].include?(@record.approval_state) || @showtype == "miq_provisions"
true
end
end