Wix Donations vulnerable to bots?

Question:
Has anybody experienced recently being attacked by a bot? We are using Wix Donations and there is no option to do a reCAPTCHA. How do I mitigate this? We received 16,000 fake donations, mostly failed, but it will cost us with the payment processor

Product:
Wix Donations

What are you trying to achieve:
I want to secure the website from bots

What have you already tried:
I tried looking for apps and options to do reCAPTCHA

Additional information:
The payment gateway is Tranzila