Hi, Halfords do them as well as others (sjs cycles).
https://www.halfords.com/cycling/bike-parts/bike-brakes/shimano-g02s-resin-disc-brake-pads?cm_mmc=Google+PLA-_-Bike+Parts-_-Bike+Brakes-_-730931&istCompanyId=b8708c57-7a02-4cf6-b2c0-dc36b54a327e&istItemId=-ltqaqrtpq&istBid=tzwt&_$ja=tsid:94971|cid:1537737090|agid:58988088472|tid:pla-330978036138|crid:291898456976|nw:g|rnd:10339739208659484386|dvc:m|adp:1o1|mt:|loc:9046928&gclid=EAIaIQobChMIvuz65I_V4QIVmLPtCh2xUwOdEAQYASABEgKwrPD_BwE
Hope this helps.