Unlike Apache, LiteSpeed requires to restart each service interacting with it. PHP isn’t excluded of this rule, so you must restart it too after changing the php.ini file.

1/ Edit the following line (here for php73):

/usr/local/lsws/lsphp73/etc/php.ini

For instance with nano:

nano /usr/local/lsws/lsphp73/etc/php.ini

use command CTRL + W to search with nano

2/ Change upload_max_filesize & post_max_size (you might consider increasing max_execution_time & max_input_time too)

 

3/ Restart BOTH LiteSpeed & WordPress:

service lsws restart && killall lsphp

And… That’s it !