Hi, the sofa is 220 x 142 x 65
This looks close:
https://www.very.co.uk/medium-gardennbspcorner-sofa-set-cover--nbsph-73-x-w-221-x-d-221-cm/1600225715.prd
Maybe not the colour you were looking for but it's an idea of the size you need, it's unlikely you'll get an exact fit unless you go custom. See list above.
This is on the large side but has tie-cords for a better fit...
https://www.very.co.uk/corner-dining-set-cover-large/1600630951.prd