Background:
Based on these API References[1][img1], the closest definition that we can find for Error Code 2 is LOGIN_ERR_REJECTED. Previously on Signaling V1, it is not required to select a data center before using the Signaling SDK.
Solution: Try and check if the Signaling feature is enabled from your console. To enable the Signaling feature, the account user must select a data center from the console version 2 page. [2][img2]
References:
[1] Signaling V2 - https://docs.agora.io/en/signaling/reference/api?platform=web#troubleshooting
[2] Console V2 - https://console.agora.io/v2
[img1] Signaling V1 API Reference:
[img2]