You enter any money coming into accounts you control.
If you have 100k worth of paychecks going into your bank account and another 18k going into your 401k
You would put 118k
If your spouse brings home another 40k, your total would be 158k.
ALSO, any debt you want paid off before FIRE needs to be subtracted from your current stash amount. If you have 100k in investments and 40k worth of car debt, you should only enter 60k into current stash.
Likewise, if you have continued debt into FIRE those payments must be added to your spending.
You wouldn't want to enter pretax values because then it will assume you're investing way more than you are.