The factory may have provided just a connection to the battery or a lot more. Your dealer may know, but it is unlikely to supply the 170 amps or so at 12 volts needed to run a 3000 watt inverter.
You will need a big battery bank, maybe 350 amp hours. 350 amp hours would supply 170 amps at 12 volts for about an hour and leave minimal reserve capacity. It will take 14 to 18 hours to recharge the battery regardless of how big your solar array is. That is just the way lead acid batteries work. Solar in summer with no shading will not provide more than 8 to 10 hours of charging.
Your TT will have to be big to carry 3000 watts of solar. Running air conditioning or heaters on 12 volts is not likely going to work well. You could use a 3000 watt inverter and 350 amp hour battery bank to run a microwave or coffee pot for short periods.
For 3000 watts, you are going to need significant sq ft of solar and a big controller. Heavy gage wire will be needed from the panel array to the controller and from there to the battery.
Many RV service centers will attempt to design and install solar. Where are you located and how far are you willing to travel to get it installed? Some one may have experience with solar installers in your area.
Dutchman Kodiak Cub KD176RD 2018
Nissan Pathfinder 2015