How do you buy weapons in War Robots?

I'm curious to know, how exactly does one go about purchasing weapons in War Robots? Is there a specific currency or resource that's required for the transaction? Are there any limitations or restrictions on what types of weapons can be acquired? Additionally, are there any tips or strategies that you can share for optimizing the weapon purchasing process in this game? I'm eager to learn more about the ins and outs of acquiring powerful armaments for my robotic warrior.