Looking for a One-room flat

I am 26 years old, male, and a nonsmoker. I don’t have pets and also do not require additional parking space. I am a tidy and well-organized person looking for a long-term arrangement as I wouldn’t say I like shifting a lot. I am currently working as a student in Fraunhofer IPMS and will be starting my master's thesis in May. Since my rental contract with my previous landlord is about to finish on March 31, 2024, therefore, I need to find decent and affordable accommodation before that.
I am looking for a 1-room apartment near city centre. I hope to get a reply from you soon in case there is availability.