Why isn't my domain rating increasing despite getting backlinks?

[NankatsuFC]

Hello, this is my website, I have got some backlinks to my website and I can see that some keywords are started to get ranked. However my domain authority is so low. I have checked on Ahrefs and Moz and on both its either 0.1 or 1. Do you have any idea why my DA is still low even after getting backlinks?

Thanks in advance,