No. Directly navigating the caller to voice mail on the first ring is not supported at present.
Voicemail is supported in situations when the 2nd Line app number recipient does not accept a call (times out) or rejects a call. In such a situation, the caller is greeted with Voicemail.
In case you need a feature to navigate the caller directly to your voicemail without a ring, please let us know. If we receive huge interests, then we might introduce a very low-cost plan that can make your number as voicemail only with an advantage to forward voicemails to you via email.