Hi and welcome. Huh what exactly are you trying to do? This it?
Plug the cable where it say LFE. Gain leave it in the middle. Low pass leave it at 80. Phase leave it at 0. Then run the AVR mic!
Just in case the LFE input on the sub doesn't automatically bypass the low pass filter, you should just set it to max. At 80 it will likely cascade/conflict the low pass filter from the avr.
OP:
Start with a sub crawl if you can to determine a reasonably good placement for the sub.
Use sub pre-out 1 from the Denon to the sub. LFE input on sub. Phase 0 if placed close to front speakers is a good start. The gain setting varies with sub, avr manual generally suggests a midway point in its adjustment, but could well need to only be at 1/4 - 1/3 range with several of the subs with plate amps I've used. Run the Audyssey/setup routine. If after Audyssey runs, the Subwoofer Level in the avr is indicated as -12 that indicates you've set your gain too high on the sub, lower the gain on the sub then re-run Audyssey....aim anywhere between -11.5 and 0 would be my recommendation.
After Audyssey finishes if the avr sets any speaker to large change it to small (or the sub can't be used, large essentially means do not use bass management for this channel, small means use bass management for this channel). I'd generally up crossovers to 80hz to start even if avr suggested a lower setting, but don't lower suggested crossovers.