this is quite advanced. two gunbots can not run over the same port. it is mentioned in the wiki.
Advanced Gunbot usage
Thanks to community feedback, Gunbot is extendable with tools from many third party devs.
Such tools will usually either interact with Gunbot over websockets, or by providing a config.js for Gunbot to load. When config.js is being overwritten, Gunbot will automatically pick up the changes, without restarting Gunbot manually.
You can also run multiple instances of Gunbot on the same machine. Automation of running Gunbot instances can be done with pm2.
pm2 is an advanced process manager for production Node.js applications. you'll need some sort of script to make the two bots running. I'm not fluent in js, so can't help you more.
another way might be to instal two gunbots, each in a dedicated folder. then, you leave one bot stock, and the on other assign different ports each to the gui and the bot. you must search for free ports on your device prior and take note.
anotherr way still is to get a VPN. you install one on your VPN and one on your home PC. or, make a virtual machine on either and run one instance on the original and one on the virtual.
now I'm out of ideas.