The sync frequencies available in your job settings depend on your Flatly Plan.
For an up to date list of available frequencies see the Frequencies section here:
During your Free Trial you will have 6 Hourly as your fastest available frequency, and Daily is the default frequency.
1 Minutely Frequency
The 1 Minutely frequency is also available under certain Steamroller+ plans:
A few of things to keep in mind regarding 1 Minutely:
Some jobs may have to sleep for N seconds to let the Data Source API cool down between runs.
If a job takes more than 1 minute to process purely because of data size, it will work on an ASAP frequency.
Stopping and starting 1 Minutely frequency jobs may take up to an hour to queue or unqueue. Be patient with the interface for these jobs.