Kim was very helpful in figuring out my problems with the airline people at the San Francisco airport. So, here is the whole story. I am writing it here so that people can understand the potential problems in having no surname on their passport. I have booked tickets with Travelopod for three of my trips to India from the USA. I had no problems for the first two trips but during my travel from SFO to Delhi in September 2023, I was not allowed to board the plane when I used my name as "FNU Anup Kumar" (where "FNU" is the first name and "Anup Kumar" is the last name). Just to clarify, my name on the passport is "Anup Kumar" (Given name is "Anup Kumar" and surname is empty). Kim helped me out to book a flight with no extra cost for two days later. My main reason for writing this elaborate comment is to be careful with the names. Even though the airline people were at fault I still had to go back from the airport that day.