Quiet a few USB-C hubs have passthrough USB-C charging. They are similar to the lightning/USB-A hub you had before, but with USB-C ports; one to connect to the iPad, one for the charger, and at least one more for external devices. They usually have a few USB-A ports as well which will probably let you use your audio sound-card. They don't cost much, but avoid the supper cheap ones. They are cheap for a reason, tend to overheat and have a high failure rate.
They often have ethernet and HDMI ports and SD card ports as well, giving you plenty of expansioin.
Search for them on
Amazon, or check out your local stores. Staples and Walmart usually care a few, though not necessarily the best.
On the far more expensive side, some keyboards offer a USB-C port that will charge the iPad, leaving gthe main port available for external devices. Only the ones that use the back pins on the iPad can do this. Bluetooth keyboards can't.
Apple's Magic Keyboard is probably the most expensive choice. There should be cheaper ones.
