I am trying to sign up from https://www.deltadna.net/signup but I get an error 500 in the console. I have tried different browsers but I get the same error.
Sorry to hear that you have run into a problem.
I have just tested the signup page and it worked fine for me. I wonder if it was a temporary issue that has resolved itself or perhaps something browser related.
Please try again and let me know if you still experience any issues.
You may also want to consider looking at Unity Gaming Services. DeltaDNA became part of Unity in 2019, so you will find most of the features of deltaDNA and whole lot more in Unity Gaming Services.
Let me know if you need any more help or information.