You could also say "regiona prononcmaniero", which is simply "regional manner of pronunciation". "Prononcmaniero" on its own just means "manner of pronunciation", so doesn't necessarily refer to a regional accent, but as far as I understand, it can encompass that meaning.

I don't see "prononcmaniero" in PIV nor in ReVo nor the Lernu dictionary; I do see it in my usual go-to, Tuja Vortaro. I also find 10 instances of it using Tekstaro de Esperanto--and beyond that all I can say is, the word came to mind because I can tell you anecdotally that I have seen people using it and have often and since long ago used it myself as a synonym for akĉento and/or to refer to someone's pronunciation in general whether I am talking about their regional/national accent or just their particular pronuncation of a certain sound or word.

I do agree that akĉento is the word you are looking for, but I thought I would bring up this other one too. I couldn't tell you specifically how I learned it, I was fairly young when I learned Esperanto and generally built up my vocabulary through (online) immersion and conversation, so my anecdotal usages might not be proper, but in my experience they are common and I don't usually find people stopping me to ask what I mean. I'd appreciate it if someone else might confirm having seen this word around, I was surprised not to see it in several dictionaries. Perhaps that's because it's a compound word but I would have thought it was common enough to have its own definition.