Using TfL Go for step-free journeys - Transport for London
they have steps and gaps you can manage, a manual ramp for boarding the train, or has designated level... buggies and some wheelchair users. These stations might have manual ramps. Steps: 51 - 120mm (2 - 4.7...-access points for getting on or off trains. (You might need these points even at level-access
https://tfl.gov.uk/maps_/using-tfl-go