Bike was in van an I had a puncture on van tyre. I didn’t put the bike back in a safe position and this has happened on the journey home.

What do u need to buy/do to fix the hose back on the lever?[url=https://flic.kr/p/qo869c]Brake[/url] by Alpine160, on Flickr

The important bit is not in focus, so hard to be precise. Looks like the hose has been ripped out, so you may be able just dismantle it, trim the last 5-10mm off of the hose and refit. It’s possible, though unlikely, that the barbed insert has snapped, in which case that’ll need replacing. Whatever, you’ll also need to bleed the brake.