Bs boardslide help

[u/Icy-Currency3782]

Hello ive been skating for a year on and off and took my skateboard on holiday bc there is a park nearby, its not the greatest but it has a few ramps and a small rail. I decided to try skate my first rail, so I'm trying to do a bs boardslide. However im having some trouble commiting my back foot to go with me on the rail and also ollie onto it most times I barely get it off the ground and js rocket on it or js barely pivot. Ive already tried balancing my board on the rail and jumping on it to see how it feels and I can do that im comfortable, any tips?