Elective Deferral for Sole Proprietor

Since a sole proprietor reports all his contributions(including any elective, if any), what triggers reporting his elective (if any) on 5500 form

In 2020 it was line

5500-EZ - 7B

5500-SF - 8a(2)

5500 - Sch I - 2a(2)

What I meant was... how would we in fact know that the contribution for the self employed was an employer contriubtion or an employee contribution, let's say, for purposes of 401(a)(4) testing on a new comp PSP/401K, with a sole prop and an employee?

He should have a deferral election form completed

17 hours ago, Bill Presson said:

He should have a deferral election form completed

Prior to the end of the tax year...