What do you do when you almost completely can’t understand someone due to accents?

I know someone who I can barely understand maybe 1 out of every 5 sentences. I’m willing to admit it might just be me. But then I feel like a complete asshole because I just keep nodding my head when I can if I think I should based on the tone of my voice. A few times I will say “apologies, I didn’t catch that,” but if I did that every single time they said something, our conversation would never progress. Sometimes they ask questions and I just bluster through an answer that sounds ok because I didn’t really understand what they’re saying.

I don’t want to be an ultra douche and make them write everything out. It could just be my bad hearing. But I have no clue what to actually do