W2 - 12a - Uncollected Medicare Tax on Tips (Code B)

For context, I work once, sometimes twice, a month at a restaurant and made no more than $1,500 for the 2023 year. I have a full time job and live in Texas. Upon reviewing my W2, I got coded “2.03 B” for box 12(a). Could someone explain what exactly does this mean and how would it impact me? Thanks!