My only knowledge of them is a cursory Wikipedia search, but yes it appears they are pro-Russia: https://en.wikipedia.org/wiki/Sahra_Wagenknecht_Alliance

We are talking about a splinter party (BSW) from the main left party (Die Linke) which is a kind of anti-woke- and anti-immigration-party that spouts basically the normal Kremlin propaganda lines about Ukraine. There is of course anti-US sentiment there since is secondary to their main issue, peace at any cost so that Germany can get cheaper energy again.

Note that I'm not a German national but I live in Germany (former DDR / East) since 9 years.

Not just in Germany but elsewhere, the rule of thumb is that libertarian socialists (anarchists etc) tend to be both anti-US and anti-Russia, while the more common and more authoritarian kind tend to be pro-whoever is anti West, including Russia, China, or places like Syria was under Assad.

They are mainly pro-communism and anti-capitalism, delve in Marxism, Lenin, Stalin, etc. and are very supportive, less critical of modern Russia. It's probably kinda like people who are supportive of the USA, don't necessarily are supportive of everything MAGA & Trump are doing, but still support it in general.