Without seeing your code I can’t really tell what’s going on but I can say this, keep the test script when forking the pen (<script src="https://cdn.freecodecamp.org/testable-projects-fcc/v1/bundle.js"></script>).
The test script should be included, with all tests passing, when you submit your project.
When installed, you’ll see a hamburger menu in the upper left, click on it and select the appropriate project and run the tests. If any fail it will show you a fail/passing and the button will be red. Click on the red button to see which test(s) failed and why.