See if can take the photo at home. https://www.gov.uk/photos-for-passports/rules-for-digital-photos Now the issue becomes if it a first passport as they needed to printed. You will have to find somewhere they will take photo that taken at home (solid white back background) from you phone and printout for you to passport size rules. It not recomended that you printed this at home as passport office most likey will not allow that print out.
