docs(srv): add doc on new auth method MTA-6708

Author: SamyOubouaziz

pages/serverless-containers/how-to/create-auth-token-from-console.mdx

@@ -20,25 +20,42 @@ This page shows you how to create and manage an authentication token from the Sc
 
 ## Creating authentication tokens from the Scaleway console
 
-1. Click **Containers** in the **Serverless** section of the side menu. The Serverless Containers page displays.
+<Tabs id="token-serverless">
+  <TabsTab label="Scaleway IAM">
+    1. [Create an IAM application](/iam/how-to/create-application/) that will be used as a principal for the policy granting access to your private container.
 
-2. Click the relevant containers namespace to see a list of containers in this namespace.
+    2. [Create an API key](/iam/how-to/create-api-keys/) for your application. Store the secret key securely, as it is only shown once.
 
-3. Click the name of the relevant container in the **Containers** tab. The container's details display.
+    3. [Create an IAM policy](/iam/how-to/create-policy/) with the following elements:
+        - **Scope**: the desired Project(s)
+        - **Principal**: the application you just created
+        - **Permission set**:  `ContainersPrivateAccess`
+    
+    You can now [use your private key as a token](#using-tokens) to call private containers.
+  </TabsTab>
+  <TabsTab label="JWT (legacy)">
+    1. Click **Containers** in the **Serverless** section of the side menu. The Serverless Containers page displays.
 
-4. Click the **Security** tab. A list of settings displays.
+    2. Click the relevant containers namespace to see a list of containers in this namespace.
 
-5. Click **Generate token** in the **Tokens** panel. A pop-up displays.
+    3. Click the name of the relevant container in the **Containers** tab. The container's details display.
 
-6. Enter the token description and set an expiration date for the token. Optionally, tick the box **No expiration date**, to have a token with unlimited validity. Then, click **Generate token**.
+    4. Click the **Security** tab. A list of settings displays.
 
-7. Copy the token from the pop-up and store it in a safe environment.
+    5. Click **Generate token** in the **Tokens** panel. A pop-up displays.
 
-    <Message type="important">
+    6. Enter the token description and set an expiration date for the token. Optionally, tick the box **No expiration date**, to have a token with unlimited validity. Then, click **Generate token**.
 
-    The token key will only be available for copy once. Make sure to store it securely before leaving the page.
+    7. Copy the token from the pop-up and store it in a safe environment.
+
+        <Message type="important">
+
+        The token key will only be available for copy once. Make sure to store it securely before leaving the page.
+
+        </Message>
+  </TabsTab>
+</Tabs>
 
-    </Message>
 
 ## Using tokens