The MAX11300 comes in two different packages, each with a different number of pins.
The TQFN package does not have any pins labeled AVSSIO, but the TQFP does (pins 24, 29, 34, 41, 44, and 48).
Although the TQFN doesn't have a pin named "AVSSIO", it still requires a voltage for AVSSIO. In this case, the Exposed Pad (EP) should be used as the AVSSIO connection.