How do I move a rental loss into a passive activity loss? I can't seem to get to form 8582.

If you had losses of less than $25,000 on rental activity and your AGI is not greater than $100,000, you will be able to take the full loss this year.  Passive loss carryovers only occur in values greater than that.  If a carryover loss is warranted, TurboTax will generate all of the documentation.

Forms mode is just not possible with the online version of TurboTax. Is this rental property the absolute only source of passive income you are reporting?

If the rental income section is done correctly, the program will create the 8582 "only if it needs it", and rental property almost always does - unless you have other passive activity with taxable income, which the passive losses can be deducted from.

Did you sell the rental property in 2019 maybe? In other words, why are "you personally" needing to change the way the program is handling it? What's the details here?