America's FARA (Foreign Agents Registration Act), passed in the late 1930s, regulates how non-American entities are allowed to fund political activities in the United States. You can read about it and see how it works at the official FRA Act website.
Yesterday the Knesset passed an Israeli version. Note that we got by without it for 62 years, until the foreign agents became so bold in their interventions in Israeli politics that some regulation became essential. Note that the Israeli law was consciously based on the American one. Note that the proposed law was watered down as it made its way through the legislative process.
Above all, note the it's a reasonable law, not a threat to Israeli democracy. Keep that in mind when you're told otherwise.