Use respond_to for request formats

app/controllers/services/lightning_controller.rb

@@ -17,11 +17,12 @@ class Services::LightningController < ApplicationController
   end
 
   def qr_lnurlp
+    respond_to do |format|
       lnurlp_url = "https://kosmos.org/.well-known/lnurlp/#{current_user.cn}"
       lnurlp_bech32 = Lnurl.new(lnurlp_url).to_bech32
       qr_code = RQRCode::QRCode.new("lightning:" + lnurlp_bech32)
 
-    if params[:format] == "svg"
+      format.svg do
         qr_svg = qr_code.as_svg(
           color: "000",
           shape_rendering: "crispEdges",
@@ -37,7 +38,8 @@ class Services::LightningController < ApplicationController
           filename: "bitcoin-lightning-#{current_user.address}.svg",
           type: "image/svg+xml"
         )
-    elsif params[:format] == "png"
+      end
+      format.png do
         qr_png = qr_code.as_png(
           fill: "white",
           color: "black",
@@ -48,8 +50,7 @@ class Services::LightningController < ApplicationController
           filename: "bitcoin-lightning-#{current_user.address}.png",
           type: "image/png"
         )
-    else
-      http_status :not_found
+      end
     end
   end