My pen is running out of ink, I need a refill.

我的钢笔快没墨水了，我需要加墨水。

youdao

I just need a refill on my pain medication.

我只需要再拿点止痛药。

youdao

I need to get a refill on this medicine.

我需要再配一次这种药。

youdao

I need to get a refill on this medicine.

我需要再配一次这种药。

youdao