Where do you find the Trade or Business ID Number for the QBI?

Here is a link for business codes:

https://www.irs.gov/pub/irs-pdf/i1040sc.pdf

Scroll down to pages 17 and 18.

This is the answer to the question "what do I enter in Schedule C line B Principal Business Code?"

But this question was still unanswered. "Trade or Business ID Number" is requested in Schedule C worksheet line C.  The principal business codes don't fit in this line. The format should be an employer ID number.  Unfortunately, it is a required field and many of us don't have an employer ID number.  Any advice?

Thanks.

If you are a sole proprietor/independent contractor, you can use a social security number.

@kaiadavid2044