Einbürgerung possible? (7 years master degree, worked at a university for 2 years, working as Ph.D. student)

Hi,

I have been living in Germany for 7 years and I have completed a master degree from German University. Then, I have worked at a university for 2 years and 3 months. In the meantime, I have received a permanent resident permit (Niederlassungerlaubnis §19 a). After that, I have been working as a Ph.D. student at the same university and receiving a scholarship of 2700 Euro per month. Additionally, I have an Integration course (B1 Telc) language certificate. I do not receive any social money and unemployment benefits. Am I eligible to apply for German nationality? Does the scholarship make any issues for my application? Thank you advance for the information!!