app.component.ts

  private conversation: Channel;

  async initialiseChatClient(): Promise<void> {
    const response = await fetch("http://localhost:8080/v1/token", {
      method: "POST",
      mode: "cors",
      headers: {
        "Content-Type": "application/json"
      },
      body: JSON.stringify({
        id: this.user.id,
        name: this.user.name
      })
    });
    const streamServerInfo = await response.json();

    this.user.avatarUrl = streamServerInfo.user.image;
    const chatClient = new StreamChat(streamServerInfo.apiKey);
    chatClient.setUser(this.user, streamServerInfo.token);

    this.conversation = chatClient.channel("commerce", "conversational-ui");

    await this.conversation.watch();
    this.conversation.on("message.new", this.onNewMessage);
  }