I want to get the list IP address of Google App Engine as of now

Question

Please help me.

Goal:

1. I want to get the list of IP address of Google App Engine.
2. It is for Salesforce to allow IP address in Salesforce settings to use a CTI/VoIP application which uses Google App Engine.

My situation:

• I found the article below, which explains that I can submit a query to get the IP address of App Engine as of now.

https://cloud.google.com/appengine/kb/#static-ip

• Using the Terminal tool, I didn't get the result of IP address.

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May I know how I can get the list of IP address?

Thank you in advance.