Online redemption of Free school meals vouchers

As an older single dad (59) I am at significant risk if I contract Covid 19. I am my son's only living relative and as such if I contract the virus and either become very ill due to my age or even worse die, my son will be placed into care. I currently have 10 weeks worth of FSM vouchers I have been unable to redeem as the only way to do so is to visit the store, risking contamination and the threat of my son being placed in care as a consequence. I have a really low income and I feel it is grossly unfair that my son should go without the £15 p/w towards buying food because Morrison's won't offer this service online.