The application must perform a check at startup to make sure the user is entitled to use the game, using the Platform SDK. For more information, see Entitlements in our Platform SDK Developer Guide."
This is what Oculus says regarding mobile submission requirments. However, I am building my project using Unity, not their Platform SDK so I am curious if I still need to do this and if yes, how do you do it?
There is a unity package in the Platform SDK. You can import that to use the entitlement checks and other platform specific functions. Be aware that there are some included scripts that require microphone permissions, so you may want to remove them if you do not require them.
More info here: https://developer3.oculus.com/documentation/platform/latest/concepts/pgsg-3-pw-platform-walkthrough/#pgsg-pw-c-unity-ent