You should be there at least 20 minutes prior to your appointment, which means 9.40 am.

Go also no use, the staffs there will only ask ppl to line up 20 min prior.
Process kinda like:
-20 min prior, staffs start calling ppl to line up
-then masuk and sit at designated waiting area
-go in for temp screening and can MySejahtera for attendance
-sit in a hall for a while, then move to corridor to fill up consent forms
-proceed to consultation, then jab
-finally, stay at observation area for around 20 min, get your vaccination card, then can balik

Overall settle in less than 1 hour jer.
yup, thats what the doctor told me during consultation session too, latest latest by 30 Jul