This user didn't write a biography yet. Mysterious, are we?
Except the fictional one in the episode is in Greenland.
Mac: Wait, isn't that the Skjaldmar International Seed Vault?
Riley: Seed vault?
Desi: In Greenland. Much like Svalbard, it's an international collaboration to collect seeds for agricultural crops.And a little later.
Matty: You three will travel to Greenland and meet with the Skjaldmar chief of police
And there are a number of other references to them going to Greenland as well. So while they mention the real-life seed vault in Svalbard, it's only to compare it to the fictional one in "Skjaldmar" that the writers created for the episode.
At least, I assume that "Skjaldmar", or the seed vault therein, is fictional.
Also, does it anyone find it odd that Brainiac-5, who is using the hashtag "AmericanAlien", is running a protest with someone displaying a sign saying "No borders! No nations!"? Last time I checked, America is a nation. Are there other countries on Earth that have passed the equivalent of the Alien Amnesty Act? What's the UN's position on refugee aliens?
That's why sometimes I think that Supergirl raises more issues than it can answer.
There were parts early-on that were played for laughs: Cliff chasing after the donkey, Vic pretending to be the ATM machine to distract the robber. But it was pretty... "straightforward" silliness/humor: no better or worse than your average DC's Legends of Tomorrow episode, or the goofier Flash episodes. Then it went off the deep-end, with Crazy Jane going... crazy, and Rita getting sucked into a donkey's mouth to end up in another dimension.
I don't watch Magnum so don't know about that. Given they tried the will they/won't they thing with Sam back in season 2 (and Nikki to some degree back in season 1), and they've both disappeared, hopefully the creative team learned its lesson.