Carry her over your shoulder and gently pat her back a few times while stroking upwards. Stand or take a walk while doing it and she will eventually burp a loud one. If baby falls asleep while feeding at times, I will usually let her sleep. Otherwise, keep baby upright for at least 20mins to prevent colic. Patience is key :)
Best is to burp your baby to prevent colic and stomach discomfort .
https://sg.theasianparent.com/burping-your-baby