If the problem is the cable or the actual charger (or “wall wart”…part that plugs into the wall), those should be easy to find about anywhere. You’re looking for a 12VDC 1.5 amp charger. The connector will be polarized. Look on the bottom of the charger, and it should have the polarity of the connector on it. It should look like the barrel connector. It will probably look something like this - —C· —+ or the reverse. THIS IS IMPORTANT!
If the problem is the connector/jack in the tablet, and they don’t have them here on iFixit, Mouser is always a good place to start. Get a part number if at all possible. Here’s a pre-filtered search for some possibilities. https://www.mouser.com/Connectors/Power-Connectors/DC-Power-Connectors/_/N-axitt