The stipend you received is taxable income. Employers usually report it on a Form 1099-MISC and report it as Other Income, not self-employment income or business income.
To report this on your return:
Scroll down to Other Common Income
Select Start or Revisit 1099-MISC and add 1099-MISC
Enter your 1099-MISC and select Continue
Enter Stipend for the description and Continue
Select None of these apply on the next screen
Select only this tax year for this 1099-MISC and Continue
Select No, it didn’t involve an intent to earn money