You can create a custom order state and order status programmatically with the help of the class Magento\Sales\Model\Order\Status.
I have just created a new order status called processing_review and assigned the status to the processing state.
You need to create Datapatch to install the new status in Magento 2.
Just create Datapatch in your module setup folder, Continue reading “How to create order status and state programmatically in Magento 2?”