Edit the following file to configure PHP parameters:
vi /usr/local/lsws/lsphp73/etc/php/7.3/litespeed/php.ini
NOTE: We are using LSPHP 7.3 as example. If you are using a different version, please adjust the number in the URL accordingly. To increase the allowed file size, for example, you would make the following edits:
upload_max_filesize = 64M
post_max_size = 64M
Other parameters in the file may also be changed, if needed. OpenLiteSpeed come with php detached mode by default, so need to restart php with command killall -9 lsphp to make settings take effect
NOTE: You have the option of using the following WordPress plugin to edit PHP directly from WordPress without doing it manually like this.
Custom PHP Settings