question

You can navigate to your title’s [Game Manager]->[Players] tab, click one player Id to navigate to this player’s [Overview] page, then click the sub-tab [Inventory] to check this player’s inventory page to determine whether the item was granted successfully or not. If you granted the item to a character, you need to navigate the player sub-tab [Characters], click the [View] button for a specific character and click the character’s [Inventory] tab to check its inventory. Please refer to this documentation - Using Player details - PlayFab | Microsoft Docs to access player details, including the player inventory, in the [Game Manager].

However, the annotation you defined in the grant item requests won’t be displayed in the player’s [Inventory] page. You can check the player’s inventory item instances and the their annotations by calling the Admin/Server/Client API GetUserInventory, if you granted the item to character, you can call the Admin/Server/Client API GetCharacterInventory to retrieve them. The annotation of every inventory item instance will be returned in these API responses.

As the above answer said, the annotation of the inventory item instances can be retrieved by API but won’t be displayed in the Game Manager. If you want to store the annotation in the place that can be checked using Game Manager, you can consider storing them as the inventory item instance custom data. You can call the Server API UpdateUserInventoryItemCustomData to set the inventory item instance custom data. So that, you can navigate to the [Inventory] page then click the gear button of item instances to access and edit these data. You can check this documentation - Using Player inventory - PlayFab | Microsoft Docs to learn more about the player inventory.