1. Log in to your RingCentral Online account.
2. Go to Phone System > Groups > Shared Lines.
3. Select a Shared Lines group that needs to be modified, then click Greeting.
4. Go to Business Hours, then below Hold Music, tick Enable.
5. Click Edit below Hold Music.
6. Click drop-down under Set Audio, then select Custom. Click Browse.
7. Select your audio, then click Done. Back to the Greeting section, click Save.
NOTE: Recommended audio file formats are CCITT u-Law (G711a), 8kHz, 8 bit, mono. The allowed .mp3 formats are PCM, 8kHz, 16 bit, mono. It is recommended to use either .wav or .mp3 audio file formats, otherwise, it will not work correctly.