Who says the employer is going to do the testing, the employer can require an employee be tested.
" business leaders can require workers to take a viral test to determine whether they are actively infected."
The person will go to what ever facility is testing, get tested, the results will be recorded on the app after 48- 72 hours the app will go from green to yellow indicating it is time for the employee to get retested. After 72 hours the app will go red to indicate the employee is no longer safe to work. JMHO