My baby has Reflux ( and is on reflux medication ) ,should I prop up his crib as they were doing in hospital ?

How old is your baby?
Were you given any instructions from the Doctor or Nurse at the hospital?
Elevating a mattress is not generally recommended. Can you reply to my questions & I will be able to provide more specific information.
https://rednose.org.au/article/my-baby-has-reflux