In the OPC UA standard, the OPC UA information model is the key to semantic interoperability. It refers to an organized structure representing resources in the form of OPC UA nodes residing in an OPC UA address space. Before runtime, an OPC UA server requires an OPC UA information model already filled with OPC UA nodes corresponding to the available resources of its field devices. It is tricky to the Industrial Internet of Things, a scenario where random field devices can join a system at any time. Indeed, the OPC UA server needs to dynamically discover such devices and update its OPC UA information model with new relevant OPC UA nodes. Regarding the above challenge, this paper introduces a Web-of-Things (WoT) approach that enables field devices to register with an OPC UA server to join the system without manual configuration. The approach relies on WoT Discovery and WoT Thing Description.