In order to translate your popups, you just need to create a new popup for each language you want to display. So once you have your main popup ready you need to duplicate it like this:
Then, once you duplicate your popup, you need to use display rules to choose the language you want to display the popup to. So for example, if the popup it’s the Spanish version you use the display rules to match the desired language like this:
“Language rule” can be found under the “Others” display rules menu and it will only appear if you have a translation plugin activated such as WPML or Polylang.