Originally Posted by hxhbk

You cannot find tickets available on VNA website because for the time being, the SGN-SFO / SFO-SGN flights are not really commercial flights.

To get a ticket you must start with the Embassy of Vietnam of the Consulate of Vietnam (San Francisco, Houston). The registration process will involve specific approved hotels for mandatory quarantine, what you can/cannot do during the first 7 days, and so on...
This is the similar process used previously for humanitarian flights to accommodate Vietnamese leaving overseas who has a dire need to return home and are willing to accept the quarantine and testing protocol in country.

The difference with this "inaugural flight" from previous humanitarian flights is that the flights are now regularly scheduled, instead on an as-needed basis previously. There may be also a price difference between the humanitarian flight and the "commercial" flight, however I am not 100% sure.
Note that there are currently only a handful of cities in Vietnam that are approved by the VN government to receive foreign visitors, Saigon is not one of them. Thus the inaugural return flight was actually SFO - DAD (Da Nang City in the Central Coast).

Local news reported that the inbound flight from SGN had 40 customers while the outbound flight to DAD had 170 pax.

The CEO of VNA has expected the flight to lose money for the next 2 years, if my memory is correct.