Lao National abroad in a country without Laos embassy/consualte

Good day to you,

First, some due introductions: My girlfriend and fiancée is from Laos, I'm from Tunisia. She's coming very soon here to Tunisia and we're planning to get a marriage certificate, which is a pretty easy and straigh forward process in my home country, in opposition to Laos regulations on marriage between Lao-foreigner. We choose to do it here, for it can take a maximum of 10 days to be officially married.

Problem is: Laos and Tunisia maintain very little diplomatic relationships, and as such, there's no Laos embassy nor consulate in here, neither does Laos have any Tunisien embassy or consulate.
She actually had to go through the Tunisian Embassy in Beijing (China) to get her Visa.

Now, one of the documents required from a foreigner wishing to marry a Tunisian National is a "permission" paper from the foreigner's embassy in Tunisia.
We have every other required document, this is the only one missing. And as Laos doesn't have any official representation in my country, we're stuck and I have no idea how this works.
I've done my research on internet, hoping to find anything related to an embassy hired by Laos in Tunisia, but I couldn't find anything useful.

So, here's my question: When a Lao National is abroad in a country without any Lao official representation, who does the Lao national address in case of problems? Say, in case of a passport loss, who does the Lao national address? Which embassy takes care of Lao nationals abroad in case of no Lao embassy/consulate?

Thank you for your answer, and I hope you have a good day!