@Ariot your computer needs to have a good internet connection while you are in your car.
To connect your car to the D5T5 app, you need a VDD Dongle, which has to be plugged in your OBD port. https://d5t5.com/article/vdash-vdd-dongle
To unlock your speed limiter, you need to decode your CEM pin first. Depending if your car is already an ICUP (Android Automotive) or a still a Sensus car, you can either decode it by brute force, or you need to buy AI premium pin decode. Modelyear 22 and newer are usually ICUP cars, so it's most likely premium pin decoding for you, as these cars can't be cracked by brute force. https://d5t5.com/article/volvo-cem-pin-code