shared.erb --- turbo_stream create error_explanation

README.md

mkdir app/views/shared
touch app/views/shared/_turbo_stream_error_explanation.erb

_turbo_stream_error_explanation.erb

<% if model.errors.any? %>
  <%= turbo_stream.update :error_explanation do %>
    <h2><%= pluralize(model.errors.count, 'error') %> prohibited this <%= model.model_name.name %> from being saved:</h2>
    <ul>
      <% model.errors.each do |error| %>
        <li><%= error.full_message %></li>
      <% end %>
    </ul>
  <% end %>
<% else %>
  <%= turbo_stream.update :error_explanation, '' %>
<% end %>

create.turbo_stream.erb

<%= render 'shared/turbo_stream_error_explanation', model: @message %>

index.html.erb

<div id="error_explanation"></div>