Streaming API

ストリーミング API では、プッシュ技術を使用してイベントのストリーミングを行い、ほぼリアルタイムでイベントを受信する登録メカニズムを提供できます。ストリーミング API の登録メカニズムでは、PushTopic イベント、汎用イベント、プラットフォームイベント、変更データキャプチャイベントを含む、複数のイベント種別がサポートされます。

• ストリーミング API アプリケーションのデバッグ

PushTopic

• Salesforce error: "Unable to create Salesforce PushTopic"
• Push Topics not working for the Asset Object

Unfortunately, these are the only supported Standard Objects -

Account
Campaign
Case
Contact
Lead
Opportunity
Task

Read this =
https://developer.salesforce.com/docs/atlas.en-us.api_streaming.meta/api_streaming/supported_soql.htm

• There was a problem connecting to the Salesforce push topic for the mapping 'Contact' and Connect is no longer receiving streaming events. Changes are only detected according to the configured poll frequency.

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Access to XMLHttpRequest at 'Org 1.lightning.force.com/cometd/52.0' from origin 'Org 2.lightning.force.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

• Streaming API support for CORS

I found the same question, so I did some research.

I assume you were setting up the connection cross domain. It appears the streaming API isn't supported.

https://salesforce.stackexchange.com/questions/179483/how-to-use-latest-cometd-version-in-salesforce-streamingapi