Hi,
You can create a new order in the backend via the "new" button on the orders listing.
Then, you can select the user, select the products, select the payment method, etc.
Once you have an order in your HikaShop, you can use the "email" button at the top to send an email to the customer with the details of the order.
If you have the "Payment of orders not paid immediately" setting activated in the HikaShop configuration, and the status of the order is one of the enabled statuses under the "Unpaid" column of the System>Order statuses menu, that email will contain a button for the payment of the order. The link will automatically use the payment method of the order.
So no plugin is required to be able to do that.