Direct link for the form is here https://enterjamaica.com/. If you complete the online C5 form, you do not use the Kisosk prior to the arrival hall. When you enter the arrival hall (end of ramp) tell the customs person you are electronic. They will direct you to an arrivals queue.
Couple of issues and recommendations.
1) Turn ff your Pop-Up and Ad Blockers on the C5 website (https://enterjamaica.com/)
2) At the end of submitting your information, you DO NOT receive a confirmation. Why they do not send a confirmation to your email is, well, very Jamaican.
3) I had one occasion (2 trips a year since they started this) where they found my submission but not the misses! Since we wanted to stay together, we both had to do the manual form process. Lost time!
4) I print out the form before submission, but suspect if there is a problem it will be useless.
5) It seems hit or miss, although last stretch in Nov 22' was problem free.
At the end of the day, when it works, it seems to save time. Regardless, the process is flawed, confusing and unpredictable. Best of luck!