Everyone has an accent. Whenever someone says they don’t have an accent, I think what they mean is that their accent is very close to some standard or accepted group. Like someone who lives in Minnesota in America could be said to not have an accent if they sound very similar to other Minnesotans. But others would say that speaking like other Minnesotans means they DO have an accent.
It’s all about how we are categorising the accent. “What do I sound like?” versus “What group do I sound like?” are often conflated. The first one relates to the sound of their voice, and how it is used to speak their language. The second relates to how close their speech is to some commonly accepted idea of how people from that area, city, or country sound. This stuff can get complex, but if I can leave you with one thing, it’s that everyone has an accent, but that’s ok 🙂