Bit off topic but here are couple of tips for e-visa application for Vietnam.
1. Before you even start application take picture of ID page of passport and also passport size photo. Even a selfie
Crop them.
2. Select your dates of travel. In my case 30 days for a single. If you accidentally enter longer than 30, no problem as it prompts you to enter period 30 days or less. The application does not requure flight details.
3. Warning: The application can be "parked" and completed later. In my experience (twice) the length of stay was changed by the programe itself. So at the Pay page make sure you review.
4. When you confirm details...It asks for first name and surname. Make sure that in the "first name" you include your middle name. In other words exactly as it appears in passport.
The fee is $25usd for single entry tourist visa and $50usd for 3 month multi entry. I used debit card (mastercard)
Process time 5 days (approx) .
The link to use for applicaction is given earlier by sandyf.
You need to print out hard copy of the e-Vias when it's emailed to you.
BTW they email you if there is an error. In my case did not include middle name
So simple.