From the description you provided, it appears as if the income would more properly be reported as Other (miscellaneous) income on Schedule 1, Line 8.
For example, a sporadic activity, not-for-profit activity, or a hobby does not qualify as a business. To report income from a nonbusiness activity, see the instructions for Schedule 1 (Form 1040), line 8.
See https://www.irs.gov/instructions/i1040sc
As a side note, you should ask your friend not to issue you a tax reporting statement or, if your friend intends to issue one, to issue a 1099-MISC. If your friend issues a 1099-NEC, and you report the income as "Other" (i.e., not subject to self-employment tax), there could be a matching problem when you file your return.
