Code:
// Task 3: Format Timestamp
println(Date.parse("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", '2021-05-24T11:42:08.875Z').format('yyyyMMddHHmmss'));
println(Date.parse("yyyy-MM-dd'T'HH:mm:ss.SSSX", '2021-05-24T11:42:08.875Z').format('yyyyMMddHHmmss'));
Output:
20210524114208
20210524214208