Water ingress passenger door

Hi All,

I seem to have water ingressing through the window seal. In the corners the seal doesn’t really fit snugly so I’m after some flexible waterproof putty like dum dum but can’t for the life of me find any at screwfix, Halfords, or Amazon with the search terms I’m using “flexible waterproof putty”

help what does anyone else use and where do you buy it from?
Thanks..in advance..

Put dum dum into eBay and similar stuff is there but on a roll. I got some last year I think.

Perfect top tip thank you. Bought some now from eBay.