Hiccups in newborn?

My hun is 14 weeks old (but was born 14 weeks premature so she’s technically a newborn). We know she suffers with reflux and we’ve got omeprazole and Gaviscon infant. We also keep her upright after feeding (she’s having breast milk in a bottle due to her prematurity).

Has anyone got any thoughts or experiences on other things that can help her with the hiccups? She gets so angry and I can’t put her down till they’ve gone.