Class TemplateInstancesApi

const instances = [
  { externalId: 'Well_a', templateName: "Well", fieldResolvers: { name: "Underwater P23", pressure: "21_PT19" } },
  { externalId: 'Well_b', templateName: "Well", fieldResolvers: { name: "Underwater P01" } },
];
const createdInstances = await client.templates.group("myGroup").version(1).create(instances);

const instances = await client.templates.group("myGroup").version(1).delete([{ externalId: ["Well_a"] }]);

const instances = await client.templates.group("myGroup").version(1).list( { templateNames: ["Well"] } );

const instances = await client.templates.group("myGroup").version(1).retrieve([ { externalId: 'Well } ]);

const instances = await client.templates.group("myGroup").version(1).update( [{ update: {
  fieldResolvers: {
    set: {
      myStringField: "My Field"
    }
  }
}, externalId: 'someExtId' }] );

const instances = [
  { externalId: "Well_a", templateName: "Well", fieldResolvers: { name: "Underwater P23", pressure: "21_PT19" } },
  { externalId: "Well_b", templateName: "Well", fieldResolvers: { name: "Underwater P01" } },
];
const createdInstances = await client.templates.group("myGroup").version(1).upsert(instances);