Look up slow paced bottle feeding! It’s recommended for breastfed babies who are getting bottles because the rate of flow is much faster in the bottles than at the breast
Adding to what others have said, pumping isn’t an indicator of supply as babies are more efficient at removing milk from the breast than a pump. It’s natural for them to fall asleep while breastfeeding as it releases those sleepy hormones.
As others have said, as long as baby is healthy and growing well, plenty of wet nappies etc they are getting enough. My LG can polish off a 5oz bottle after already having a bit of a feed some mornings plus want a feed after too and falls asleep on the boob almost every time, she's using me as a dummy to nap right now haha. But she's gone from 2nd centile to 9th after getting her tongue tie cut being ebf (was 0.4th centile before then too with lots of pumped top ups while we waited for the appointment) so I know she's getting enough.
I have a 10 month old here, exclusively breast feeding. Pumping isn’t indicative of what they get when latched! If baby has plenty of wet diapers, gaining weight based on her growth curve, and isn’t fussing after being breast fed, you can rest assure that she’s getting what she needs. Mine has always fallen asleep while nursing during nap time and at bedtime. And he’s a big boy! 21 pounds at 6 months. He’s super quick when nursing throughout the day, like 3 minutes and he’s done.