If students in both classes have individual devices (e.g., mobile phone, tablet, laptop, etc.)...

Use a platform such as Google Meet, Zoom, or Microsoft Teams which allows you to screen-share during a video call. 
One educator should set up the Kahoot! game and share the code with students in both classes by following this tutorial about using Kahoot! in a remote learning environment, and share their screen so everyone can follow along.

If students in either class don’t have individual devices...

Follow the same instructions above, with one educator starting the game and sharing their screen so both classes can follow along.  
Instead of students joining the game to answer the questions, they can hold up their fingers, call out their answer, or use a paper template to indicate their response.

If you prefer not using Kahoot!...

Use this document (Spanish version) to prompt students.

Additional Resources