Sched C or Sched 1 ?

I retired in 2023, but did a one-time contract software job for my former company in 2024 for $5k

They won't send me a 1099-NEC so I need to report this elsewhere.

 

Should I use a Sked C or a Sked 1?

(I am not a business and will not be doing more of this)

 

tia