Although over 88% percent of browsers support the backdrop-filter CSS property, which is important to obtain the "glassy" look, unfortunately, Firefox disabled this feature by default (although it can be enabled from the settings page).

As a fallback for the Firefox browser issue, you can add a much smaller transparency to the card using the @-moz-document url-prefix() CSS rule.

Glassmorphism is being used on the web here and there, look at this navigation bar for example: https://headlessui.dev/react/menu

You can try out the free community edition: https://www.figma.com/community/file/973638860086718856