Advice please to stop leak on my pressure washer at the hose connection | Terry Love Plumbing Advice & Remodel DIY & Professional Forum

I tried plumbers tape but it leaks really bad..I hope there is something I can do, that maybe I don't know about.
There's a knob on the pressure washer that I turn to thread it onto the hose end..it's not easy to turn because it's located right next to the wheel but it's seems tight enough.