How do I get repository credentials

[#1]

I use HDP 3.1.4 and ambari 2.7.4.0

When adding a data node, the following error occurs.

failure: repodata/repomd.xml from ambari-2.7.4.0: [Errno 256] No more mirrors to try.
http://public-repo-1.hortonworks.com/ambari/centos7/2.x/updates/2.7.4.0/repodata/repomd.xml: [Errno 14] HTTP Error 403 - Forbidden

What do i do?

Thank you.