Show form errors

app/assets/stylesheets/application.scss

@@ -1,3 +1,7 @@
 // Sassy
 
-@import "bootstrap";
+@import "bootstrap";
+
+.error-message {
+  color: var(--bs-danger)
+}

config/initializers/form_errors.rb

@@ -0,0 +1,13 @@
+ActionView::Base.field_error_proc = proc do |html_tag, instance|
+  if html_tag.include? "<label"
+    appended_html = ""
+    if instance.error_message.is_a?(Array)
+      appended_html = "<div class='error-message form-text'>#{instance.error_message.map(&:humanize).uniq.join(", ")}</div>"
+    else
+      appended_html = "<div class='error-message form-text'>#{instance.error_message.humanize}</div>"
+    end
+    html_tag + appended_html.html_safe
+  else
+    html_tag
+  end
+end