Ip rotation in php script

We had a .php script made that contacts a website and start a search there. Now the website is blocking the ip adrress from the server the script runs at. I’m looking for someone to modify the script by adding a spoofing the ip every 5 minutes so the address is not banned from any new search.
NOTE !!! I dont want to buy ip adresses for this or anything. The adjustment to the script needs to use free to use ip adresses to work with.