How to Enable MSI Support in Magento 2 Auto Invoice & Shipment Inventory Extension
By default, after the installation of the Auto Invoice & Shipment extension, MSI support is enabled.
If you disabled the MSI and Plumrocket_AutoInvoiceShipmentInventory extension before, but now you want to use MSI, you have to enable the module again. To do this, execute the following command in the terminal:
php bin/magento module:enable Plumrocket_AutoInvoiceShipmentInventory