I'm no expert but I had a quick test experiment with same thing your'e trying.

I connected a valve amp with power soak & speaker emulation to line in of USB audio interface.

Telecaster single coil pickup, hi gain, and CRT monitor - so predictable nasty loud hum..

All I did was select Audacity Noise Reduction pre-set

and it automaticlly eradicated the hum, to the extent that it was nearly inaudible.

Interesting side effect, was that it is not a transparent process.

The recorded guitar rhythm lead track also had significantly less bass and lower mid frequencies.

Which was actually an unforseen benefit, as it sounded almost like
the guitar had been recorded using a vintage Rangemaster treble booster.