How do I add money to my Flamingo app?

Excuse me, could you please explain how one might go about adding funds to their Flamingo app account? I'm new to using the app and I'm a bit unsure of the process. Is there a specific payment method I should be using, or are there multiple options available? Additionally, is there a fee associated with adding money to the app, and if so, how much is it typically? I'd appreciate any clarity you can provide on this matter. Thank you in advance for your assistance.