Build up the time she can be left slowly.
Get her keen for the kong, let her see and smell you filling it before you go the first few times and only give it as you leave, then walk out no fuss. Leave her for ten minutes and when you come in, give her a treat and pick it up. It helps to have several kongs as they get mucky
Let us know how you get on.

Meant to say the aim is for her to
Go 'yay food and fun' when she sees the kong not 'oh no' so be as inventive as you can with stuffing it in te early stages Lots of threads on here about kong stuffing ideas. Definitely think of investing in a food release toy, or at the very leadt throwing a proportion of her dry food
On the floor as you go out.

No joy with leaving her so far. She was left in kitchen with toys for an hour yesterday but after us strengthening the dog gate she still got out into living room by scrambling over the gate. (My daughter forgot to give her kong which may have helped) two main concerns 1. She could hurt herself falling back into kitchen onto hard tiled floor 2. Any longer in living room and she could start to chew settee etc..... We are really struggling to leave her in any safe place to go shopping for say 2 hours and general day to day stuff....

Any tips advice ...??? Please we are struggling to leave the dog for any more than 10 seconds as she starts barking and scratching at doors