Checkout with paypal without login

I am trying to implement paypal express checkout using rails. I have
at lot of places that if one wants to do the checkout without paypal
account by credit or debit card one can simply useSOLUTIONTYPE=Sole. It
does not seem to work though and asks for login when I try to checkout.
Please find the attached screenshot which shows this problem.

def pay
topup = Topup.find(params[:id])

    response = EXPRESS_GATEWAY.setup_purchase(topup.price_in_cents,{
      :ip                => request.remote_ip,
      :currency_code     => 'GBP',
      :return_url        => topups_success_url,
      :cancel_return_url => topups_cancel_url,
      :SOLUTIONTYPE => 'Sole',
      :items => [{:name => "Topup", :quantity => 1,:description => 

“Top up my account”, :amount => topup.price_in_cents}]
redirect_to EXPRESS_GATEWAY.redirect_url_for(response.token)