Behind popup

Hi all.
I’ve installed and configured, and it works fine.
But, when user needs select images to solve captcha, the windows appear behind my popup.
I’m thinking in use z-index BUT captcha uses inline CSS with 2000000000 value.
I wanna change and fix this without modify the pluging.
Ty

https://ww.wp.xz.cn/plugins/gravity-forms-no-captcha-recaptcha/