Add information about api keys (ton-community#729)

* Add information about api keys

* Remove info about tariffs

---------

Co-authored-by: Full-Hat <nikita3131228@gmail.com>

Author: 2 people

docs/develop/dapps/apis/api-key.mdx

@@ -0,0 +1,33 @@
+# Api keys
+
+## Overview
+
+When using the TON HTTP API, a `token` (`key`) is generally not required. However, it unlocks request limitations. There are several available plans, all of which can be viewed in Toncenter mini app
+
+## How to Get a Key
+
+To get a key, visit [@tonapibot](https://t.me/tonapibot), press the `start` button, and follow the instructions.
+
+![Telegram Bot](/img/registration-process/telegram-bot.png)
+
+Press the `Manage API Keys` or `Toncenter` button to open the Telegram mini app.
+
+![Toncenter Main Mini App](/img/registration-process/toncenter-main-miniapp.png)
+
+Press `Create API Key`.
+
+![Create API Key](/img/registration-process/create-api-key.png)
+
+Fill in the required fields and press `Create`. That's it! The key can now be used for sending requests.
+
+## How to Update the Subscription Plan
+
+To update your subscription plan, follow these steps:
+
+- Click the `MANAGE` button at the top of the app; a window with plans will open.
+- Choose the required plan and click `Purchase Subscription`.
+- Send the required amount of TON to the proposed address.
+
+## Troubleshooting
+
+If your Telegram app is outdated, the mini app may not work properly. Try updating the Telegram app.

sidebars.js

@@ -298,6 +298,7 @@ const sidebars = {
             'develop/dapps/apis/README',
             'develop/dapps/apis/toncenter',
             'develop/dapps/apis/adnl',
+            'develop/dapps/apis/api-key'
           ],
         },
         {