As you electric vehicle's battery gets critically low on charge it will normally begin to restrict performance to try and preserve battery range for as long as possible. This is often referred to as 'Turtle mode', and will typically activate with around 5-10 miles of range left.
These battery-saving modes will slow your car so acceleration is gentler and maximum speed is much lower. When you get to zero miles, the car might keep going for a few more miles but eventually will come to a gentle halt. You will need to call for roadside assistance. Some EV's come with an SOS button where it calls the Manufacturer call centre and they organise the rescue for you (there may be a cost for this service).
See also: https://electrictogether.com/get-help/what-happens-if-i-run-out-of-battery-and-get-stuck-or-breakdown