I have a shareholders basis worksheet on my K-1 and need to input allowed losses
TurboTax does not have a form for tracking the shareholder basis for a K-1 recipient. You will need to track that calculation outside of the program. The IRS Instructions for Form 1120S Schedule K-1 at this link have a worksheet and instructions for tracking your shareholder adjusted basis.
This link has a "fillable" PDF of that IRS adjusted basis worksheet, in case you need a worksheet to attach to your tax return.
Such a worksheet is required by the IRS to be attached to your return in certain circumstances, which are explained in detail in this link to the IRS Instructions for Schedule E, Basis rules for S corporations.