Cannot Get Extensions to Work on Ubuntu 16.04 with PHP7.2

PHP SDK
1 
Error:  Uncaught Error: Class 'Couchbase\PasswordAuthenticator' not found

Output of php -v:

PHP 7.2.11-2+ubuntu16.04.1+deb.sury.org+1 (cli) (built: Oct 15 2018 11:40:04) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.2.11-2+ubuntu16.04.1+deb.sury.org+1, Copyright (c) 1999-2018, by Zend Technologies

Output of: php --ini

Configuration File (php.ini) Path: /etc/php/7.2/cli
Loaded Configuration File:         /etc/php/7.2/cli/php.ini
Scan for additional .ini files in: /etc/php/7.2/cli/conf.d
Additional .ini files parsed:      /etc/php/7.2/cli/conf.d/10-opcache.ini,
/etc/php/7.2/cli/conf.d/10-pdo.ini,
/etc/php/7.2/cli/conf.d/15-xml.ini,
/etc/php/7.2/cli/conf.d/20-calendar.ini,
/etc/php/7.2/cli/conf.d/20-ctype.ini,
/etc/php/7.2/cli/conf.d/20-curl.ini,
/etc/php/7.2/cli/conf.d/20-dom.ini,
/etc/php/7.2/cli/conf.d/20-exif.ini,
/etc/php/7.2/cli/conf.d/20-fileinfo.ini,
/etc/php/7.2/cli/conf.d/20-ftp.ini,
/etc/php/7.2/cli/conf.d/20-gd.ini,
/etc/php/7.2/cli/conf.d/20-gettext.ini,
/etc/php/7.2/cli/conf.d/20-iconv.ini,
/etc/php/7.2/cli/conf.d/20-json.ini,
/etc/php/7.2/cli/conf.d/20-mbstring.ini,
/etc/php/7.2/cli/conf.d/20-phar.ini,
/etc/php/7.2/cli/conf.d/20-posix.ini,
/etc/php/7.2/cli/conf.d/20-readline.ini,
/etc/php/7.2/cli/conf.d/20-shmop.ini,
/etc/php/7.2/cli/conf.d/20-simplexml.ini,
/etc/php/7.2/cli/conf.d/20-soap.ini,
/etc/php/7.2/cli/conf.d/20-sockets.ini,
/etc/php/7.2/cli/conf.d/20-sysvmsg.ini,
/etc/php/7.2/cli/conf.d/20-sysvsem.ini,
/etc/php/7.2/cli/conf.d/20-sysvshm.ini,
/etc/php/7.2/cli/conf.d/20-tokenizer.ini,
/etc/php/7.2/cli/conf.d/20-wddx.ini,
/etc/php/7.2/cli/conf.d/20-xmlreader.ini,
/etc/php/7.2/cli/conf.d/20-xmlrpc.ini,
/etc/php/7.2/cli/conf.d/20-xmlwriter.ini,
/etc/php/7.2/cli/conf.d/20-xsl.ini,
/etc/php/7.2/cli/conf.d/20-zip.ini,
/etc/php/7.2/cli/conf.d/30-couchbase.ini

Output of: php -m

[PHP Modules]
calendar
Core
couchbase
ctype
curl
date
dom
exif
fileinfo
filter
ftp
gd
gettext
hash
iconv
json
libxml
mbstring
openssl
pcntl
pcre
PDO
Phar
posix
readline
Reflection
session
shmop
SimpleXML
soap
sockets
sodium
SPL
standard
sysvmsg
sysvsem
sysvshm
tokenizer
wddx
xml
xmlreader
xmlrpc
xmlwriter
xsl
Zend OPcache
zip
zlib

[Zend Modules]
Zend OPcache
2

@thetoad01 please make sure that you are running your PHP script with CLI (in your terminal), and not in the apache server, because it seems like you running php -m in the terminal and you are posing the output for CLI version of config: /etc/php/7.2/cli/conf.d/30-couchbase.ini