The Stoke Newington Church Street entrance to Abney Park Cemetery is closed for renovation until 14th October 2022.
This means it is not possible to follow the route through the cemetery.
An alternative route is shown in the walk guide that you can download from this web site. The map here is a detail from the related map in the guide.
The good news is that once the entrance is reopened it will be step-free so will improve the accessibility of the route.
Note that the main entrance to the cemetery on Stoke Newington High Street is open for those who want to visit/explore the cemetery.)