eVisa flight question

Hi all, I'm looking for guidance for an upcoming trip that we're planning to Thailand. We hope to travel in about 6 weeks, and my partner is from an African country and needs an evisa. My question is regarding the requirement to show proof of your flight, as we want to avoid potentially wasting money on a flight (given that this will be a couple of grand for them round trip) if the visa isn't granted. I have seen recommendations of buying a fully refundable ticket, but I've also heard that people have trouble getting their money back with certain airlines that we might have to fly with. Is this how others have done it, or have people successfully gotten visas with dummy tickets, etc. to avoid potentially wasting money before the visa is granted? Thank you!