Step - 1: If you are unsure about the php version installed,
then first run the following command in terminal
php -v
Output: the above command will output the php version installed on your machine, mine is 7.2
PHP 7.2.3-1ubuntu1 (cli) (built: Mar 14 2018 22:03:58) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
with Zend OPcache v7.2.3-1ubuntu1, Copyright (c) 1999-2018, by Zend Technologies
Step 2: Then to install phpize run the following command, Since my php version is 7.2.3. i will replace it with 7.2, so the command will be,
sudo apt-get install php7.2-dev
Step 3: Done!
Alternate method(Optional):
To automatically install the phpize version based on the php version installed on your machine run the following command.
sudo apt-get install php-dev
This command will automatically detect the appropriate version of php installed and will install the matching phpize for the same.