Where do I enter one time consultant income paid by check without a 1099

If your self-employment income was only from cash, personal checks, credit card payments, or cryptocurrency 

Type Schedule C in the Search box and then select the Jump to link. This will take you to where you can enter any cash, personal checks, credit card payments, or cryptocurrency (Form 1099-K) related to your self-employment. You may first be asked some general questions about your business. After you answer them, you’ll be taken to the Let's get income for (your line of work) screen where you can enter this income as Additional Income.

In addition to the information provided by @xmasbaby0, note that if you also have expenses to report, and are unable to proceed in TurboTax with a Schedule C on the return, it may be that you have a TurboTax product that is not designed to prepare a complete Schedule C. If you use Deluxe, for example, you can report income from self-employment but not all expenses. The full Schedule C can only be found in Turbo Tax Self-Employed for online users, or Home and Business for desktop/download product users.

If the payment you received was for a one-time event, and you don't regularly do independent contractor work, then you could designate the income as a "sporadic" activity in TurboTax and not need to prepare a Schedule C or Schedule SE. 

Please see this thread for a detailed discussion of a similar topic with other examples and options.

Please also see this TurboTax help article for more information about self-employment tax.

See this TurboTax Tips article for more information on preparing returns with Schedule C.

@idembny