working out

How many minutes per day should a pregnant woman exercise in third trimester? I'm not high risk. Working out such as walking and elliptical with maybe some 8lb weights. The reason I ask is bc I logged in over 60 mins option on this app and it said women in third trimester shouldn't workout over an hour or something along those lines
I might add ive gained 33 lbs already at 32 weeks and break it up. I usually do 30 mins-twice per day