The shekalim in parshas shekalim which talks about the machzis hashekel used to count klal Yisrael has a specific tikkun for Haman and Amalek.
The question is simply what’s the connection between the two? How does the idea of the machsitz hashekel relate to the defeating of Amalek?
Chazal tell us that the machsitz hashekel was one of the few things that Moshe Rabbeinu didn't quite grasp the first time it was told to him. Tosafos in Menachos (39a) asks, how is it possible that Moshe didn't understand what a machsitz hashekel was? Its a simple half-shekel?! Tosafos says that surely Moshe knew the physical coin that each person was required to give. Rather, Moshe didn't understand how such a thing could be a kapparah. The idea behind the machsitz hashekel was something which escaped Moshe. In order to further explain the idea, HaShem showed Moshe Rabbeinu a "matbeiah shel aish", a "coin on fire", and from that Moshe understood the yesod of the machsitz hashekel.
What does this mean? How did a flaming coin further explain to Moshe Rabbeinu the kapparah of the machsitz hashekel?
I heard an explanation from my previous Rebbe at the Mir, Rav Vagshal. Rav Vagshal explained: Whats the sin that the machsitz hashekel was coming to fix? It’s clarified in chazal that there’s a certain issur to count people. We see this by Dovid hamelech who sinned by counting people and a plague resulted. In order to have a kapparah for such a sin, HaShem gave the mitzvah of the machsitz hashekel. Why? Where’s the Takkana of the sin? Rav Vagshal explained that if a person would take a bag of coins, it would exists as a bag full of coins. Even though the bag may hold them all, they each will always exist as a separate coin. Fire, however, is different. If a person joins together two flames, they don't continue to exist as two separate flames, rather they combine and become one.
This is what HaShem showed Moshe. That when the coins are given l'shma, they're not just coins which exist separate from one another, rather they come together like fire. It results in an achdus, one people with one goal; to serve HaShem. This fire could be a tikkun for the sin of counting- for counting by definition separates each person as an individual. The machsitz hashekel is what united us after such a separation.
This is also the reason why chazal instituted to read shekalim before Purim. When adar begins is when shekalim were used in the Purim story. But theses shekalim aren't just any shekalim. They're a direct tikkun to Amalek. One of the foundations of Amalek was to create a separation. The yesod of the machsitz hashekel is the fire. There are no separate flames, only one fire.
The Zohar says that before the days of moshiach, five types of Eirev rav will present themselves. The Zohar explains that the first type of people come from the root of Amalek. They try to uproot klal yisrael from Torah, our definition, our fire which connects us. In such a time when people seek to separate us from Torah and each other, the only way to combat it is with the yesod of the machsitz hashekel. To enforce our fire and join it with our fellows. Only then can we become one and conquer the yesod of Amalek.