Note: For configuring Workflow Manager on a server that is NOT part of the SharePoint 2013 farm, you must install the Workflow Manager Client on each server in the SharePoint farm before you run the pairing cmdlet.
For downloading and installing the Workflow Manager Client go here
To configure Workflow Manager on a server that is NOT part of the SharePoint 2013 farm and on which communication takes place by using HTTP
1. Log on to each server in the SharePoint Server 2013 farm.
2. Install the Workflow Manager Client on each server in the SharePoint farm.
3. Open the SharePoint Management Shell as an administrator. This is accomplished by right-clicking the SharePoint 2013 Management Shell command and choosing Run as administrator.
4. Run the Register-SPWorkflowService cmdlet. The cmdlet should be run only once and can be run from any of the servers in the SharePoint farm.
Register-SPWorkflowService -SPSite "http://myserver/mysitecollection" -WorkflowHostUri "http://workflow.example.com:12291" -AllowOAuthHttp
To configure Workflow Manager on a server that is NOT part of the SharePoint 2013 farm and on which communication takes place by using HTTPS
1. Determine whether you need to install Workflow Manager certificates in SharePoint 2013.
2. Log on to each server in the SharePoint Server 2013 farm.
3. Install the Workflow Manager Client on each server in the SharePoint farm.
4. Open the SharePoint Management Shell as an administrator. This is accomplished by right-clicking the SharePoint 2013 Management Shell command and choosing Run as administrator.
5. Run the Register-SPWorkflowService cmdlet.
Register-SPWorkflowService -SPSite "https://myserver/mysitecollection" -WorkflowHostUri "https://workflow.example.com:12290"