Link error.
Link working for me...
Try copy pasting it into Signal itself for a new chat https://signal.group/#CjQKICKP4m5jPiL-RdDH1Nx9ZapzJxd_YHwqsNVwGx-ABrezEhCuG2_aSzYcnl3mm5NBFO0x
I'm using Molly (which is on the latest update and have already set up my username), so that might be why it isn't working, which is a bit annoying.
Ah. Derp. I forgot to uninstall signal and that caused an issue with the link routing to Molly. 😅