If I have two student loans with same distributor (nelnet) how do repayments work?

Is it 1500 total towards all loans or 1500 per loan (or 15% yada yada).

Have:

3600 with rate of 4.99%/year 4600 with rate of 5.5%/year

Seperate loans but same distributor.

A year from anniversary date will January 2026.