For one of our projects we are exploring capabilities of Omnichannel.
Below are the steps for provisioning the Omnichannel for Dynamics 365 Customer Service for quick reference.
Posts on Omnichannel for Customer Service (Dynamics 365)
First, we need to make sure we have the Customer Service Hub already installed.
https://trials.dynamics.com/

Next, we need to have an active subscription of Chat for Dynamics 365 Customer Service or Dynamics 365 Digital Messaging
The other options
https://docs.microsoft.com/en-us/dynamics365/omnichannel/try-channels
Navigate to Microsoft 365 Admin Center
https://admin.microsoft.com/
Select Purchase services
à
Add-ons

Select Dynamics 365 Customer Service Digital Messaging Add-on trial.

And also assign the add-on license to the users who need to work with Omnichannel Service.

Login to Data access consent URL using the Global Tenant Admin account and give the consent.

We’d be presented with the below message.

Login to Dynamics 365 Administration Center and navigate to Applications Tab and click on manage for Omnichannel for Customer Service.
https://admin.powerplatform.microsoft.com/environments


This opens the Manage environment page for Omnichannel.
Click on Add Environment to add the environment.

Here we can select the environment to which we want omnichannel solutions to be configured.

Click on next and we can then add chat as one of the channels.

Click on Next to similarly setup SMS, Social, and Microsoft Teams as the channels.



Click on Finish to start the installation.


It will show the status as Installed after some time. (took around 1 and half hour in our case)

To manage the channels or delete the omnichannel we can use the same Manage option for Omnichannel for Customer Service in the Applications tab within Dynamics 365 Admin Center.

We can use the Delete button to remove the Omnichannel configuration à

We’d also see the Omnichannel Administration and Omnichannel for Customer Service apps in the list of Dynamics 365 Apps.

Get all the details here
https://docs.microsoft.com/en-us/dynamics365/omnichannel/administrator/omnichannel-provision-license
Hope it helps..