How do I add new terms (class resources) to the Open Research Knowledge Graph

You need a particular term from a controlled vocabulary for describing a scholarly paper and this term does not yet exist in the Open Research Knowledge Graph. You can add it to the ORKG as a class resource (go to View > Classes), and here you can create a new class resource to which you can refer in your paper descriptions (Create class). For creating a new class, you have to provide the class label and the URI, if you are using a class from an external controlled vocabulary or ontology. After you have created the class resource, you can edit it by adding statements to it and assign an ORKG template to it. You can also import instance data for that class (i.e. individual resources that are members of the class - that instantiate the class) from a csv file.