fix(mdb): fixes2

Author: ldecarvalho-doc

pages/managed-mongodb-databases/how-to/manage-users.mdx

@@ -37,8 +37,9 @@ When you create your MongoDB® Database Instance, the first user is created by d
 You can create more users and grant them pre-set roles via the [Scaleway Managed MongoDB® API](https://www.scaleway.com/en/developers/api/managed-database-mongodb/).
 
 <Message type="important">
-  All users you create have at first administrator roles, which can be changed after creation with the [Update a user on a Database Instance](https://www.scaleway.com/en/developers/api/managed-database-mongodb/#path-users-update-a-user-on-a-database-instance) call.
+  All users you create have at first administrator roles, which can be changed after creation with the [Apply user roles](https://www.scaleway.com/en/developers/api/managed-database-mongodb/#path-users-apply-user-roles) call. The default user's role cannot be changed.
 </Message>
 
 
 
+