where is API key?

[dice10240]

I was told that if I want to retrieve MSRC API key, then I need to go to

https://portal.msrc.microsoft.com/en-us/developer

but it shows json file, and link tells I am accessing

https://api.msrc.microsoft.com/cvrf/v3.0/swagger/v3/swagger.json

Article tells we can access developer tab and gain API key.
I login with outlook.com account.

This is Japanese blog.
https://msrc.microsoft.com/blog/2017/04/sug/

Can you please help me.
Thanks