First, assign a public IP address to the remote machine on GCP.
Run gcloud compute config-ssh to add automatically the VMs of your project to your ~/.ssh/config or add public IP manually.
Use the Hostname of the remote to connect in your Deployment configuration in PyCharm
Select the remote server from the drop-down and point PyCharm to the executable python of your Python installation.
Thus you can use PyCharm interpreter with a compute engine.
For more details, refer to the below tutorial on google cloud training.