Chronic hiccups. To stop the hiccups.

My father aged 66 years is experiencing continuous hiccups (chronic) from last three days. Recently he is discharged from hospital where he was taking covid treatment. He got steroid dexa 4 mg twice for three days there. After which he developed hiccups, we gave pantop injections for two days, but the hiccups just stopped for few hours and again continued. From last three days, we are giving mucaine, metaclopramide (thrice a day), and beclofen 5 mg once a day. But the hiccups stops just for few hours and again continues. Please suggest permanent solution to it. Now my father is having pain due to the continous hiccups as well as he feel very week as he is not able to eat food due to chronic hiccups. Please suggest something to stop the hiccups. Thanks