Hi Queen Mak!
First of all, thank you for your support!
If you want to constantly donate every month, I recommend my Patreon account ^.^-
For one-time donation, I recommend through my Ko-Fi or through the itch.io game page, where you can download the demo and pay what you want for it~ There's also a Paypal button at Bermuda's game page. If you click on it, you can become a backer and get some benefits (like, there's an early bird pack where you can get the game for $10, there's also packages with artbook, walkthrough, etc...)
I hope this helps!