You can create calls for Omnichannel conversations using any of the conference call providers. The default provider is the one you set when configuring conference calls.
To be able to create calls for Omnichannel conversations, set the call provider by following these steps:
Go to Administration > Workspace > Settings > Omnichannel > Video and Audio Call > Call Provider.
Select Default Provider.
To learn how to use conference calls as an Omnichannel agent, see Omnichannel Conversations - Call.