PHP has parameters to control the maximum uploading size. Here, we use Ubuntu 18.04 LTS default version as an example.
Then, find the following parts
; Maximum size of POST data that PHP will accept. ; Its value may be 0 to disable the limit. It is ignored if POST data reading ; is disabled through enable_post_data_reading. ; http://php.net/post-max-size post_max_size = 20M
; Maximum allowed size for uploaded files. ; http://php.net/upload-max-filesize upload_max_filesize = 20M
and change them to the size you prefer.
Last, restart apache2 to make the new parameters take effect.
$ sudo systemctl restart apache2