OWCP has put up more guidance for federal employees with regard to injuries and illnesses arising from the Covid-19 pandemic which you can find at this link:
It is unclear as to how these cases will be adjudicated by OWCP. Generally speaking, a medical condition is work related if more likely than not work contributed to your condition. Your doctor will need to discuss the possible and confirmed sources of exposure both on the job and off the job, and then explain why its more likely than not that you contracted Covid-19 in the performance of your federal employment duties.
For medical and law enforcement federal employees there is an acknowledgement of the high risk nature of work duties exposing someone. However, other federal employees have jobs that involve interaction with the public and will have a harder time with this. I think that a report outlining that for eight hours a person was interacting with coworkers and the public and addressing the possible sources of exposure outside of work, and then explaining why its "more likely than not" that the person was exposed to the virus on the job, is what is needed. "More likely than not" just means 50+%, if you picture a scale tilted ever so slightly one way, that is "more likely than not." I fear that some physicians will decide that since they don't know where you got exposed, they cannot say that its related. But remind your doctor that its only "more likely than not." The doctor need not be concerned that its possible it happened elsewhere, but the doctor must be able to explain why, when weighing the various ways someone was exposed, its more likely than not that the exposure happened in the performance of work duties.
Some people are going to become overwhelmed by mental health conditions about this situation. If you develop a mental health condition due to how your work duties put you at risk, that can also be accepted as a work injury so long as its explained sufficiently in a narrative report by either a licensed clinical psychologist with a relevant doctorate (PhD, PsyD, or EdD) or a psychiatrist.
There has not been an event like this during the lifetime of anyone presently in the workforce, so these are going to be difficult cases as we move forward.
As a federal employee, you are due medical care, lost wages, and, perhaps, a schedule award.