In my case, I used a Bangkok based translation service. I remained in Phuket the entire time this was done (back in year 2020 if i recall correctly). I sent my passport by courier to the Translation Service, and they did all the leg work between the Canadian Embassy and the Thai Ministry of foreign affairs. With my passport (to the Translation Service) was a performa document granting them Power of Attorney for this specific activity. Once it was all done, they couriered everything back to me. In fact, I did this, not to get a Yellow Book, but did it to have my marriage to my Thai wife registered in Thailand. Ubon Joe (bless his memory) recommended i adopt this method. Later, I used the official translation to get a Yellow Book and Pink ID.
