Reason 1: The SIP account for calls has been disabled. It is necessary, according to the instructions, to turn it on again. Possible reasons for shutdown:
- the account has not been used for a long time (more than 3 months);
- an account with an identical login/password/server address was added by another user;
- The SIP server reported that the account no longer exists/is unavailable.
Reason 2: The settings for the number conversion rules have gone wrong. Open the SIP account settings in the @siptg_bot bot and make sure that the correct rules are used. Or reset them by entering the value =. (the period at the end is important)