We need to locate the php.ini file on the Ubuntu Server and then switch to that directory.

:~$ cd /etc/php/8.1/apache2/
:~$ /etc/php/8.1/apache2/$
:~$ /etc/php/8.1/apache2/$ ls
:~$ /etc/php/8.1/apache2/$ php.ini

Edit php.ini using vim or nano.

:~$ vim php.ini 

Within the php.ini file, locate and modify the following settings to read as follows, and enable date.timezone by deleting the leading semicolon ';date.timezone ='

memory_limit = 512M
upload_max_filesize = 500M
post_max_size = 500M
max_execution_time = 300
date.timezone = America/New_York

Here is another author's similar list for making changes. For the basic nextcloud deployment, change the default options using the following configuration.

file_uploads = On
allow_url_fopen = On
memory_limit = 512M
upload_max_filesize = 500M
post_max_size = 600M 
max_execution_time = 300
display_errors = Off
date.timezone = Europe/Amsterdam
output_buffering = Off

Save and close the php.ini file when you are finished. Then, start the Apache and MySql service and enable them to start after system reboot with the following commands:

sudo systemctl reload apache2
sudo systemctl start apache2
sudo systemctl start mysql
sudo systemctl enable apache2
sudo systemctl enable mysql

These commands will run like the following.

:~$ sudo systemctl reload apache2
[sudo] password for user:
        OR
:~$ sudo systemctl start apache2

:~$ sudo systemctl start mysql
:~$ sudo systemctl enable apache2
Synchronizing state of apache2.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable apache2
:~$ sudo systemctl enable mysql
Synchronizing state of mysql.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable mysql
:~$