I learned from this document:

https://developers.thomsonreuters.com/tr-eikon-scripting-apis-eap-limited-access/eikon-web-and-scripting-apis-beta/quick-start

but I did not see the [Gererate a new Application ID ] bottom,why?

The pic your can see on :

https://i.loli.net/2018/06/07/5b1889772eafe.png

<img src="https://i.loli.net/2018/06/07/5b1889772eafe.png" alt="trquestion.png" title="trquestion.png" />