How do I report a stipend payment if I did not receive a 1099 from the organization?

Report it as "other income" on Schedule 1 line 8z. Here's how to enter it in TurboTax.

• In the Search box in TurboTax type "executor fees" (without the quotes), then click the link that says "Jump to executor fees." I know that's not what the payment was for, but it's the best search term I could find that gets you to the right place.
• The first screen asks, "Any Other Taxable Income?" Click Yes.
• On the next screen, "Other Taxable Income," enter a short description such as "Stipend" and enter the amount. Click Continue.
• On the next screen click Done.
• You will get a couple more screens with unrelated questions. If they don't apply to you, just answer No and click Continue.

The income will be reported on Schedule 1 line 8z with the description that you entered.

Stipends are usually reported as taxable scholarship. After entering your 1098-T, you will be asked if you had an scholarships not shown on the 1098-T. Answer yes.  When asked if any was used for room and board, answer yes. Then enter the amount you want to be taxable (usually all of it), in the pop up box. R&B are not "qualified educational  expenses".  So, this is how you tell TT that it is taxable. Note the wording at that screen “or other expenses”. You didn’t have to literally use the scholarship for R&B.  This will put it on line 8r of Schedule 1 (this line is new for 2022).

No 1098-T? 

Enter at Educational Expenses and Scholarships, under Deductions and credits (not the income section). After answering no to having a 1098-T, answer yes to qualifying for an exception (that gets you to the entry screens). You will have to go thru the whole education interview to get to the scholarship screen. 

You now have two answers telling you to do it differently. Neither answer is wrong,  The income can go in either place.  It is usually better, for a student-dependent, if it is entered on line 8r, of Schedule 1, as scholarship.

"Other income", on line 8z of Schedule 1, is classified as unearned income. Scholarships are a hybrid between earned and unearned income. It is earned income for purposes of the $12,950 filing requirement and the dependent standard deduction calculation (earned income + $400).  It is not earned income for the kiddie tax and other purposes (EIC. IRA contributions).

A dependent's standard deduction is the higher of $1150 or his earned income + $400, but not more than $12,950.  Example: student-dependent's only income is $8000 stipend, not on a W-2.  If he reports it as other income, his taxable income will be $8000 - 1150 = $6850.  If he reports it as scholarship,  his taxable income will be $8000 -  $8400 = 0