Good question. The answer depends on the situation. I am never a fan of asking a buyer to pay my commission. I think this should be handled by the seller. 80% of fsbo's roughly will cooperate and agree to pay a buyer's agent their share of the commission. This is often a win-win as the seller saves half of a typical commission and still gets to pay the buyer's agent their fair share for the work they will do on behalf of the buyer to close that deal.
There will always be the people out there who had a successful FSBO transaction and will say how easy it is, but for every one of those there are two that went poorly for the parties involved.
I know many people will laugh at this but buying or selling a home is a better process when handled by a professional who does it every day. Just like a lawsuit is better handled by a lawyer and an injury is better handled by a doctor. In both cases, you pay more, but you know you are getting the care and attention of a professional. Why should real estate be any different?
So, my best advice is this. If you have a home in mind that is FSBO contact an agent to help (If it is local you can call me) and ask them to reach out to that FSBO for you. Best case, they will work with your agent which is great. Worst case, they won't but at least you tried to go that route first.