You can change this in the ACP.
I was running NodeBB 16.x and recently updated to 17.x → 18.x → 19.x and somewhere along the way the API that TripleA (board game software that posts to my forum) uses had a breaking change. Looking through the changelog, I can't figure out which change it was.
For reference here's the issue on TripleA. The stack trace may not be useful here but just in case..
Looks like an API changed from returning a list to returning a map.
Found your breaking change:
remove deprecated v2 style responses for thumbs upload route [breaking] (84dfdfe6)
@pitaj Awesome, thank you!