How to configure settings.xml file in Nexus server for proxy maven mirror

Hi Team

I work in Data Platform team in which we use Talend as ETL software.
We are facing some issue to configure a proxy maven repository in our On-Premise Nexus3 server for download third-part libraries in the Talend repository at URL:
https://talend-updates.talend.com

using this guide:
https://help.sonatype.com/repomanager3/nexus-repository-administration/formats/maven-repositories
Because we use a proxy.
In fact the above guide tell us to configure in Nexus Server, in our Maven file directory, the file settings.xml for the in the directory .m2, e.g ~/.m2/settings.xml
So checking on our nexus3 on-premise set-up, we only find this file:

/data/nexus/system/settings.xml

That is actually empty.

We don’t know how to go forward and how to eventually configure the settings.xml file.
May you provide us support?
Thank you for let us know.

Gianluca