Convert "Rise100", "Business Class Pro Bike" from (EU) 350w E-bike to a 450w Moped by disconnecting the white wire in the control box under the rear rack using the chassis number and "Single Vehicle Approval" form.

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/973873/motorcycle-single-vehicle-approval-application-form.pdf

To walk or climb stairs press the handlebar red button first then depress the LCD bottom button for 3 seconds and start up the power, unclip, tilt the seat, then you're ready to concourse walk at 4mph.

Further, you can now climb stairs placing yourself towards the middle of the bike with a straight posture to ascend, but only when converted to 450w.
 
You lift 25% of the weight at the front while pushing the rear knobbly tyre into the front corner of the stairs giving grip for the motor wheel to ascend stairways.
If you have to stop, always switch off the walk switch immediately, every time to prevent static over heating and the electric safety cutting out.