Hello Erin,
Thank you for posting to the Microsoft community. I'll be providing answers to your question.
To clarify your situation,
- Is your Surface Pro currently connected to the internet?
- Is Find My Device enabled on the Surface Pro?
- Are you using an Android or iOS phone to access your Microsoft account?
If your Surface Pro is listed under your Microsoft account and Find My Device is enabled, then yes, you can remotely lock it from your phone. Here's how:
Steps to Remotely Lock Your Surface Pro
>> Go to: https://account.microsoft.com/devices on your phone browser.
>> Sign in with the same Microsoft account linked to your Surface.
>> Select your Surface Pro from the list of devices.
>> Click Find My Device.
>> If the device is online, you’ll see its location. Click Lock.
>> Follow the prompts to:
> Display a message on the lock screen (optional).
> Require your Microsoft account password to unlock the device.
Make sure your surface must be connected to the internet, location services and Find My Device must be enabled on the Surface, also you must be using the same Microsoft account on both the Surface and the device you're using to lock it.
Best Regards,
Favour | Microsoft Community Support Specialist