If you are on the Premium or Enterprise plan, all that you need is the email of the other platform's administrator, as well as their platform domain (something.skyprepapp.com).
To share your course, navigate to the course you want to share by clicking on Teaching, then Courses, then clicking on the course itself. Click on the General Settings tab. Once there, scroll down until you see Share Course Between Platforms. Click on Share Course.
You will then be prompted to enter the admin's email and platform domain, as well as an option for Allow Course Duplication. This option, if enabled, will allow the other admin to copy the course and modify it as if it was their own.
Please keep in mind that the only settings that are carried over are Course Introduction, Course Name, and Course Image. Other settings such as Prerequisites and Deadlines will be reset to their default values.
Once satisfied, click Share Course.