Challenge Overview
History has failed us, but no matter.
Server source
There are two flags in this challenge. Submit flag one here, and flag two in Pachinko Revisited.
Website
Solution
wget https://challenge-files.picoctf.net/c_activist_birds/7eac27979c12e4bd449f03e40a8492044221b7d2a96ac85f1150e30983c56eac/server.tar.gz
To see the source you can use tar -xvf server.tar.gz however it's not really needed for this challenge.
You can just spam the submit circuit button until the pop-up gives the flag. If you don't feel like typing it out manually you can see all the POST requests even after closing the pop-up in the Network tab and just copy the flag. Every iteration of submission says success but only occasionally does it give the flag.
Flag: picoCTF{p4ch1nk0_f146_0n3_e947...}