Many of the low powered hardware found online come without power supplies. This can often be an advantage, as many users will already have suitable power supplies and can benefit from cheaper hardware.
Most hardware will use either a Micro-USB cable or a USB-C cable and prices can start from $1-$2 USD.
This cable can then be plugged in to USB ports on laptops, battery packs, Wi-Fi routers and many other power sources to power your Learner’s Block. If however, you want to run the hardware on the mains power supply, you will also need a plug that allows you to plug your USB cable into the relevant wall socket.