Transport for London (TfL) have now re-introduced the requirement touch-in to pay on many bus routes, including the Route 193 which serves the eastern side of Emerson Park. However, safety restrictions which have been brought in mean that bus capacities are greatly reduced and TfL are still asking people only to use buses if your journey is essential.
For the latest TfL advice on bus travel, see their website. For up-to-date details of changes to bus boarding and touching in changes, see this link.