See https://jcallaghan.com/2019/08/replicate-sharepoint-hub-site-navigation/ for more information. See https://gist.github.com/jcallaghan/c4da343cfd55c97a3592879199190dfb for full script. #Website

Hub Site.json

{
  "headerEmphasis":null,
  "themeKey":null,
  "name":"SharePoint Hub Site",
  "url":"https://[tenant].sharepoint.com/sites/[site]",
  "logoUrl":null,
  "usesMetadataNavigation":false,
  "megaMenuEnabled":true,
  "navigation":[{
    "Id":2004,
    "Title":"Heading",
    "Url":"http://linkless.header/",
    "IsDocLib":false,
    "IsExternal":false,
    "ParentId":1002,
    "ListTemplateType":0,
    "AudienceIds":null,
    "Children":[]
  }],
  "isNavAudienceTargeted":false,
  "siteDesignId":"00000000-0000-0000-0000-000000000000",
  "requiresJoinApproval":false,
  "hideNameInNavigation":false,
  "parentHubSiteId":"00000000-0000-0000-0000-000000000000",
  "relatedHubSiteIds":null
}