A single member LLC does not produce a K-1, as it has no need to. The IRS considers a single-member LLC as a disregarded entity. Therefore all income/expenses are reported on SCH C as a part of your personal tax return.
If this is a multi-member LLC, or an LLC that has filed form 8832 to be "treated like an S-Corp" for tax purposes, then you have to use TurboTax Business to complete the IRS Form 1065 for the partnership LLC return, or form 1120-S for the S-Corp return.
TurboTax Business is not available as an online product or for MACs. It's for Windows only. Purchase it at https://turbotax.intuit.com/small-business-taxes/