You can read about it here- the station had to register as a foreign agent with the DOJ:
https://en.wikipedia.org/wiki/WZHF
https://www.washingtonpost.com/media/2022/03/07/radio-sputnik-wzhf/

one of only five outlets in the United States that air English-language broadcasts of “Radio Sputnik,” produced in Moscow and Washington under the Russian government’s supervision.

Sputnik is the radio and digital arm of Rossiya Segodnya (Russia Today), the same Kremlin-controlled media agency that directs RT and RT America, the better-known TV and digital media operations founded by Putin’s regime in 2005.

But while American distributors and European governments have banned RT since Russia’s attack on Ukraine, leading to the collapse of RT’s American operations on Thursday, WZHF is still offering Sputnik’s content to Beltway listeners.

With names like “Political Misfits” and “By Any Means Necessary,” its talk shows are as slickly produced as anything on NPR or the giants of conservative talk radio. Some discussions — organ transplantation, recycling and paranormal activity were among last week’s topics — are apolitical. But many Sputnik hosts offer more barbed commentary about America’s perceived flaws: racism, economic inequity and political dysfunction. One consistent thread for years: Skepticism of the U.S. intelligence community’s conclusion that Russia acted to influence the 2016 election in favor of Donald Trump.

Sputnik’s talking heads have tended to justify Russia’s invasion of Ukraine, alleging Ukrainian “crimes” against its Russian-speaking population and “encroachment” on Russia from the NATO alliance. They typically describe the invasion as “a military operation” or “an intervention,” echoing Putin’s framing. There’s plenty of whataboutism: A Russian commentator on Friday fretted that the United States could give nuclear weapons to Ukraine. “We cannot be confident that America will be a responsible member of the international community,” he said.

WZHF has been licensed to a New York company, Way Broadcasting, since 2001, according to FCC records. But Way appears to be a largely passive owner. In 2017, it agreed to lease the station’s airtime to a second party, RM Broadcasting of Jupiter, Fla.

RM, in turn, sold all of the station’s airtime to Rossiya Segodnya and Sputnik. RM made a similar deal in 2020 with Alpine Broadcasting to place Sputnik’s programs on Alpine’s three stations in the Kansas City area.

The practice, known as a time-brokerage agreement, has been a financial lifeline for small and financially troubled broadcast outlets since the 1930s. Instead of hiring a sales staff and producing programs, station owners merely lease blocks of airtime to another party, often through a broker, which puts its own programs on the air. The best-known form of such agreements are TV “infomercials.”

Sputnik’s deals have been lucrative for the broadcasters involved. According to federal filings, RM paid Way Broadcasting $1.12 million last year to air Radio Sputnik full time and Alpine Broadcasting about $160,000 to carry Sputnik for six hours a day on its Kansas City stations.

RM’s owner, Arnold Ferolito, defended Sputnik in a recent interview, saying efforts to remove it from the air were an attack on free speech.

“RM Broadcasting stands with Ukraine and victims of oppression and aggression worldwide,” he wrote in an email. “One of the fundamental rights that Ukraine is fighting for is freedom of speech and freedom from censorship, and RM is dedicated to the unfettered exchange of information and ideas.”

He noted that the stations disclose Rossiya Segodnya’s role as the source of the broadcasts throughout the day “so that people may make an informed decision on whether to listen or turn the dial.”

Ferolito said other American station owners wanted to carry the service, too, but Sputnik’s parent organization “did not have the budget” for wider U.S. reach.