It would be nice if Spacelift, via the Spacelift backend, could natively support triggering a remote plan run using the relevant terraform or tofu command, similarly to what TFC and Env0 support.
In other platforms, assuming you have the correct backend configured and have run the correct terraform login command then you can run `terraform plan` from a local machine and have it trigger a remote run of the plan and stream the logs back to the local instance.