score:5
The border authority will trust you if you provide a print out of insurance. If it is forged, then its a crime. If detected, you will be charged and you may have to pay fine or possible jailtime.
I think its deterrent enough for a document like this.
Furthermore, you will have to pay for treatment and isolation expenses out of your own pocket, if you get covid, which will be much more than what you have "saved".
Upvote:2
I was in Vietnam a few weeks ago. While I had an insurance certificate, it was never checked by airline staff or immigration/customs at all. Your mileage may vary.