Below are all the instructions for installing Tiny Tiny RSS on Ubuntu. It should work on other Linux distributions but I haven’t tested it. Be sure to follow the instructions in order because in my testing you can break the LAMP server if you do not.
-Login to your server using PuTTY and navigate to your web root.
cd /var/www/html
-Use the git clone command to download tt-rss to your web root.
sudo git clone https://tt-rss.org/git/tt-rss.git tt-rss
-Install the dependency software packages for tt-rss
sudo apt install php-mbstring php-fdomdocument php-intl php-curl
-Restart apache
sudo systemctl restart apache2
-Navigate to the newly downloaded tt-rss folder.
cd ./tt-rss
-Change permissions for some of the tt-rss folders.
sudo chmod -R 777 cache/images
sudo chmod -R 777 cache/upload
sudo chmod -R 777 cache/export
sudo chmod -R 777 feed-icons
sudo chmod -R 777 lock
-Login to MySQL Create new MySQL user
mysql -u root -p
mysql> GRANT ALL PRIVILEGES ON *.* TO 'ttrss'@'localhost' IDENTIFIED BY 'password123';
mysql> exit
-Log back into MySQL using the new user account and create database.
mysql -u ttrss -p
mysql> CREATE DATABASE ttrss;
mysql> exit
-Go to your web browser and go to the install page http://yoursite/tt-rss/install/

-Change Databse type to Mysql
-Enter username you created in mysql
-Enter password for that user
-Enter the database name you created
-For host name enter localhost or leave blank
-Enter port 3306
-Click Test Configuration and make sure it says “Configuration Check Succeeded” and “Database Test Succeeded”

-Click Initialize Database
-Copy the automatically generated configuration file presented.

-Go back to PuTTY and create the config.php file in the tt-rss folder.
sudo nano /var/www/html/tt-rss/config.php
-Paste config in the newly created nano text file
-Press CTRL + X to exit then press Y to save the changes then press ENTER to keep the file name the same.
-Go back to your web browser and navigate to tt-rss http://yoursite/tt-rss/ login using the default username and password
Username – admin
Password – password
-It will ask you to change the password select go to preferences then click the user tab then select the user.

-Now we will log back in using the new password you have selected.
-Go back to preferences by clicking action in the upper right and and the preference tab then change the Default update interval to 15 minutes or whatever you want.

-Now we need to setup the update process. go back to PuTTY and create the service file.
sudo nano /etc/systemd/system/tt-rss.service
-Enter the below text and save the text file.
[Unit]
Description=ttrss_backend
After=network.target mysql.service postgresql.service
[Service]
User=www-data
ExecStart=/var/www/html/tt-rss/update_daemon2.php
[Install]
WantedBy=multi-user.target
-Once its pasted in the new document press CRTL + X to exit then press Y to save and ENTER to keep the file name.
-Start the service
systemctl start tt-rss
-Set the service to run at boot
systemctl enable tt-rss
-Reboot the server
sudo reboot
-That’s it. You are now complete and can use your new instance of Tiny Tiny RSS to subscribe to RSS feeds and read the internet more efficiently.
Here is the video version of the tutorial.