How do you get more Red Coins?

Could you please elaborate on the process of acquiring more Red Coins? Are there specific tasks or activities one needs to undertake in order to earn them? Additionally, are there any limitations or restrictions in place that one should be aware of when trying to accumulate Red Coins? It would be great if you could provide a detailed breakdown of the most effective strategies for acquiring Red Coins, along with any tips or insights you might have to help streamline the process.