ICT Billet 3/4" to 3/4" Inch Hose Barb Splice Coupler Repair Fitting Adapter Connector Radiator Coolant Intercooler Heat Exchanger Fluid Designed & Manufactured in USA Bare Aluminum AN627-12A

Hard to see but if that is at the rear of the engine near the firewall, it’s the heater hose connector. I got this part from Amazon, replace with a metal version https://a.co/d/0a6fEPnL

ICT Billet 3/4" to 3/4" Inch Hose... https://www.amazon.com/dp/B07G3JY5J8?ref=ppx_pop_mob_ap_share