Refer to this tutorial for how to setup a scheduled script
Step 1: Get your IP Update Link
a. Login to http://quickstart3.unotelly.com/
b. Click on Networks.
c. Copy the IP Update link for Step 4.
Step 2: Open the Terminal
In the upper right corner of your screen, where the search function is, type in Terminal and open the program.
Step 3: Open your crontab
Type in: crontab -e and press Enter.
If you already have a crontab, it will open the existing one, otherwise it will create a new one for you.
Step 4: Add in the custom CronJob
Press "i" on the keyboard to put the text editor in insert mode. Then paste in the following:
0 * * * * curl -L -o /dev/null http://www.unotelly.com/unodns/auto_auth/hash_update/updateip.php?user_hash=YOUR_HASH_HERE
Note that between the each of the asterisks, the "0" and between the last asterisk and curl there are tabs used, and not spaces. Remember to replace the IP update link or YOUR_HASH_HERE with your own from Quickstart.
Step 5: Save and Quit
Once you have pasted the above line in cron, press the ESC key on the keyboard to exit the insert mode. Then type in ":wq" and press Enter.
You should then see crontab: installing new crontab in the terminal indicating that the cron job was added successfully. That's it!
This will update your IP address every hour.