Square kitchen sink plug

[Zorinindustries]

I got a kitchen from Homebase about 5 or 6 years ago. The sink had a square plug hole.

But the plug has broken and I want to buy a new one.

I can't find one anywhere, not even the Homebase website.

Does anyone know where i can buy these? Thanks

E bay have them:
www.ebay.co.uk/itm/265254578828?chn=ps&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&itemid=265254578828&targetid=1279902198379&device=c&mktype=pla&googleloc=1006849&poi=1006614&campaignid=12689626702&mkgroupid=124353408922&rlsatarget=pla-1279902198379&abcId=9300529&merchantid=7383914&gclid=CjwKCAjw1JeJBhB9EiwAV612y9FI3Iclynr1TNISBhu0tRBitBPE0wJHeO08hJvDXkeMvubAVXddYhoCON8QAvD_BwE

So do Amazon. Just google "square sink plug"

Thanks, you are star.
I googled it and found nothing then looked on DIY shops website. No idea why I didn't think.of amazon!!!