Block Websites without FamilyActivityPicker

I want to block specific Websites with FamilyControls in my App. To do this, I need to access the WebDomainTokens of a specific Website, without the user selecting it in the FamilyActivityPicker. I basically just want to have a button e.g. "Block Instagram" and when clicking it, the instagram website is blocked. I don't see any way in accessing the WebDomainToken without the FamilyActivityPicker. Or is there maybe another approach to this problem?

Currently I tried the following:

var selectionToDiscourage = FamilyActivitySelection() {
    willSet {
      let applications = newValue.applicationTokens
      store.shield.applications = applications.isEmpty ? nil : applications
      let webDomain: WebDomain = .init(domain: "https://www.instagram.com/")
      print("TOKEN: \(webDomain.token)")
      print("DOMAIN: \(webDomain.domain)")

      if let webDomainToken = webDomain.token {
        let webDomainTokenSet: Set<WebDomainToken> = [webDomainToken]
        store.shield.webDomains = webDomainTokenSet
      }
    }
  }

But when only giving the domain, the token always prints nil. Hope someone can help!