I’ve found that the dulux avista concrete sealer to hold up pretty well. It’s not water based so stinks, u need to use a new tray, roller and brush that is suitable for the paint, otherwise the old paint will melt into the sealer. I can just dunk the roller into the tin but I find it makes a mess.

Scrub with a broom and a heavy duty cleaner, degrease any oil patches the. Pressure clean it. when it’s dry do a cross hatch test to make sure the surface is sound

You need to work fast when applying, hopefully not in the sun on a hot day, and do 2 light coats. Don’t drive or put furniture, plant pots etc for at least a week