TI-API: Error 403 - Implementation of the backlog push APIs is required to use the quote API.

Tool/software:

Hello
I'm trying to go to the next page 

https://www.ti.com/swc/developer-apis/backlog/backlog-order-api/push-notification-api-setup.html

And I get the 403 error message

Error 403

You don't have permission to access this page. If you think this is a mistake, try these steps:

• Restart your browser
• Clear cookies in your browsing data
• Disable ad blockers in your browser's privacy settings

If these steps didn't work, contact support.

I try with another userfrom my organization who invited me to register and with this user I succeed
Why do I not have the permission and what can be done so that I will not be limited in contacting you
Thanks