Travelers must complete the "Travelers Health Surveillance Form" online.
Travelers entering Kenya are required to present a negative COVID-19 PCR test result issued within 96 hours prior to travel that has been digitally verified through the Trusted Travel (TT) Initiative. Persons traveling to Kenya from countries not yet party to the Trusted Travel Initiative must use a tool made available through the Global Haven partnership for COVID-19 test results and vaccine certificates verification.
Children under the age of 2 are exempt from presenting a COVID-19 test.
Travelers with proof of recovery from the virus within the last 90 days prior to boarding. Proof of a recent positive viral test and a letter from your healthcare provider or a public health official stating that you were cleared to travel.
More info at the CDC site
Travelers who did not get tested, are advised to stay home and self-quarantine for 10 days after travel.