ActiveAdmin.register ApiKey do
  permit_params :access_token

  index do
    column :id
    column :access_token
    default_actions
  end

  filter :access_token
  
  show do |user|
    attributes_table do
      row :id
      row :access_token
    end

    active_admin_comments
  end

  form do |f|
    unless f.object.new_record?
      f.inputs "Api Key Details" do
        f.input :access_token
      end
    end
    f.actions
  end
end

ActiveAdmin.register ApiKey do

  index do
    column :id
    column :access_token
    default_actions
  end

  filter :access_token
  
  show do |user|
    attributes_table do
      row :id
      row :access_token
    end

    active_admin_comments
  end

  form do |f|
    f.actions
  end
end
--- 
+++ 
@@ -1,4 +1,5 @@
 ActiveAdmin.register ApiKey do
+  permit_params :access_token
 
   index do
     column :id
@@ -18,6 +19,11 @@
   end
 
   form do |f|
+    unless f.object.new_record?
+      f.inputs "Api Key Details" do
+        f.input :access_token
+      end
+    end
     f.actions
   end
 end
Allow editing of access token
