External Conversion Tracking on a Different Domain

Hi,

I know we can track external conversions like this:
https://documentation.unbounce.com/hc/en-us/articles/203879180-Setting-Conversion-Goals

but, is there a workaround to track conversions on a different domain?

Example:
www.landingpageA.comhttps://differentwebsite.com/thank-you
www.landingpageB.comhttps://differentwebsite.com/thank-you
www.landingpageC.comhttps://differentwebsite.com/thank-you
www.landingpageD.comhttps://differentwebsite.com/thank-you

Cheers
Veronica