I disposed my entire interest in a Partnership Fund. Form8582 shows my loss as an Unallowed Loss. I have no 1099B, can I enter the loss to show up on my 8949?

As you scroll through the partnership entries on the K1, in the section that says Describe the Partnership, indicate you disposed a portion of your interest in the partnership in 2022. The next screen will say Tell Us About Your Sale. Here you you will make a choice how you disposed of your interest.

Next screen will indicate purchase dates and sales date. Next screen will ask you to enter the sale information. If you lost your entire investment, put 0 for sales price and then under Partnership Basis, you will list your initial investment. This will show a loss.

Now this will show up as an ordinary loss on Form 4797 and will not appear on a 8949 or Schedule D as a capital loss.