fix port

apps/block_scout_web/lib/block_scout_web/templates/api_docs/eth_rpc.html.eex

@@ -2,9 +2,9 @@
   <div class="card">
     <div class="card-body">
       <h1 class="card-title margin-bottom-sm"><%= gettext("ETH RPC API Documentation") %></h2>
-      <p class="api-text-monospace" data-endpoint-url="<%= BlockScoutWeb.Endpoint.url() %>/api/eth_rpc">[ <%= gettext "Base URL:" %> <%= BlockScoutWeb.Endpoint.url() %>/api/eth_rpc ]</p>
+      <p class="api-text-monospace" data-endpoint-url="<%= BlockScoutWeb.Endpoint.url() %>/api/eth_rpc">[ <%= gettext "Base URL:" %> <%= url() %>/api/eth_rpc ]</p>
       <p class="card-subtitle margin-bottom-0">
-        <%= gettext "This API is provided to support some rpc methods in the exact format specified for ethereum nodes, which can be found " %> 
+        <%= gettext "This API is provided to support some rpc methods in the exact format specified for ethereum nodes, which can be found " %>
 
         <a href="https://github.com/ethereum/wiki/wiki/JSON-RPC"><%= gettext "here." %></a>
         <%= gettext "This is useful to allow sending requests to blockscout without having to change anything about the request." %>

apps/block_scout_web/lib/block_scout_web/templates/api_docs/index.html.eex

@@ -2,7 +2,7 @@
   <div class="card">
     <div class="card-body">
       <h1 class="card-title margin-bottom-sm"><%= gettext("API Documentation") %></h2>
-      <p class="api-text-monospace" data-endpoint-url="<%= BlockScoutWeb.Endpoint.url() %>/api">[ <%= gettext "Base URL:" %> <%= BlockScoutWeb.Endpoint.url() %>/api ]</p>
+      <p class="api-text-monospace" data-endpoint-url="<%= BlockScoutWeb.Endpoint.url() %>/api">[ <%= gettext "Base URL:" %> <%= url() %>/api ]</p>
       <p class="card-subtitle margin-bottom-0"><%= gettext "This API is provided for developers transitioning their applications from Etherscan to BlockScout. It supports GET and POST requests." %></p>
     </div>
     <div class="api-anchors-list">

apps/block_scout_web/lib/block_scout_web/views/api_docs_view.ex

@@ -1,7 +1,7 @@
 defmodule BlockScoutWeb.APIDocsView do
   use BlockScoutWeb, :view
 
-  alias BlockScoutWeb.LayoutView
+  alias BlockScoutWeb.{Endpoint, LayoutView}
 
   def action_tile_id(module, action) do
     "#{module}-#{action}"
@@ -33,4 +33,12 @@ defmodule BlockScoutWeb.APIDocsView do
       "&#{param.key}=" <> "{<strong>#{param.placeholder}</strong>}"
     end)
   end
+
+  defp url do
+    if System.get_env("BLOCKSCOUT_HOST") do
+      "http://" <> System.get_env("BLOCKSCOUT_HOST")
+    else
+      Endpoint.url()
+    end
+  end
 end