rns5.spectrumretailnet.com is a server login page, not a business you'd shop from or sign up for. The homepage simply says connections are logged and unauthorized access is prohibited. That's a clear sign this is an internal system, likely used by a retail network's staff or administrators.
From a security standpoint, the site does well: it forces encrypted connections, blocks clickjacking, and has a valid certificate. No malware or phishing flags have been reported. But the domain has no history in the Wayback Machine and no public WHOIS information, which is common for internal servers but means you can't independently verify who operates it.
If you're an employee or contractor with legitimate access, this is probably a normal login page. For everyone else, there's no reason to interact with it. Don't try to guess passwords or submit any personal data. The site isn't a scam, but it's also not a place for consumers. If you're looking for a retail service, this isn't the right address.