PHP 7.2 says Yaz functions are undefined

Question

I have installed yaz library (see phpinfo below). The yaz.so is in the proper extension folder, it shows up in my phpinfo (see below).

Yet when I attempt to use any of the functions, php says undefined.

What am I missing?

From phpInfo()

PHP Version 7.2.9-1+ubuntu16.04.1+deb.sury.org+1
---------
yaz
YAZ Support enabled
PHP/YAZ Version 1.2.2
YAZ Version 4.2.30
Compiled with YAZ version   4.2.30