Signature verification error while installing

I am installing atom editor like this.

$ wget -c -O atom.x86_64.rpm

$ sudo zypper install atom.x86_64.rpm

But when I reach into the installation step I get this message:

The package is not signed!

atom-1.56.0-0.1.x86_64 (Simple RPM file cache): Signature verification error [6-The file is not signed]

How can I proceed?

Thank you deer community.