Typically, the hub will choose the best driver for your device when the device is added to your hub. In unusual cases, you may need to change the driver by yourself for some reason, including:
To change the driver:
Navigate to Devices, find the device in the list, and select the device to pop up its device detail page or flyout.
Select the Device Info tab at the top of the device detail page.
Select the dropdown under Type, and select your desired driver from the list:
Select Save after selecting your new driver.
In most cases, it is recommended to run the Configure command (on the Commands tab), if available, after switching drivers.
If your driver did not select the correct driver when added and you are not sure which built-in driver to use, consult the compatibility list: List of Compatible Devices. If you cannot find your device on this list and believe it should work with the hub, the "Generic Z-Wave...," "Generic Zigbee...," and "Generic Matter..." drivers should work with most devices of the matching type (e.g., switch, dimmer, etc.) and protocol.
If you are trying to use a custom driver, the driver must be added to your hub first. The driver developer or manufacturer may have instructions for how to add the driver to your hub, or see: How to Install Custom Drivers. Note that Hubitat cannot offer support for these drivers, but the third-party developer may.