Pull Requests in GitHub doesn't include the speculative plan link back to Terraform Cloud

Problem

When creating a new workspace in the TFC UI.  A user is able to trigger runs from TFC UI successfully, however when creating a PR in Github it does not include the TFC speculative run link back to this workspace.  The webhook has all the necessary admin permissions for the TFC workspace.  

Cause

• As part of creating a new workspace by default the Automatic speculative plans flag located at https://app.terraform.io/app/$Organization-name/workspaces/$workspace-name/settings/version-controlby under the Speculative section is disabled.
• To allow speculative plans, the Automatic speculative plans flag would need to be enabled by placing a checkmark in the field and saving the workspace
• Once enabled, the speculative plan link to Terraform Cloud will be included in the Github PR

Solutions:

• Go to https://app.terraform.io/app/$Organization-name/workspaces/$workspace-name/settings/version-controlby and enable the Automatic speculative plans flag under the Speculative section and save the workspace. 

• Now the speculative link will exists In the Github PR under the Conversation tab and about midway down the page should contain anAll checks have passedsection for the PR.  The right of that block should display the show all checkshypertext link. Click on it and that will uncover theDetails section which includes the aforementioned speculative plan link 

Additional Information

• For additional assistance please contact HashiCorp Support