is a visa needed for a layover

is a visa needed for a layover
Dear Sir/Madam. I'm planning to fly to Sydney and have a layover in Vietnam. I'm considering leaving the airport for some sightseeing. Could you tell me if I need to apply for a visa in order to leave the airport?
Regards
Dear Sir/Madam,
Thank you for your question.
We would like to inform with you that you have to apply for a Visa if you want to leave out of Vietnam international airport and enter Vietnam for sightseeing. We would like to advise you to apply for 1 month single type of Visa for the cheapest expense.
You can apply online with us to get your Vietnam Visa at Vietnam international airport at: vietnam-evisa.org/apply-visa.html
Best regards,
E-visa team.