MEATER Block is powered by the AA batteries and does not have a rechargeable internal battery. The purpose of the micro USB port is to provide an alternative power source for long cooks, but plugging in your MEATER Block will not recharge the AA batteries. For this reason, we don't include a charging cable with the product or sell them separately.
If you do want to plug in your MEATER Block to save batteries, the port is compatible with any 5V micro USB cable. These come included with a lot of small electronics, so you might even have one around the house already! If you don't, they're pretty inexpensive, and are easy to find at any physical or online store that sells small electronics. Whenever possible, though, we recommend keeping your batteries in all the time and not relying on the cable.