No, you are not allowed to use a VPN or any sort of GPS spoofing device. Our Terms of Service clearly outline this in Section 6:
"By accessing, using, or visiting any of our Games & Services, you agree not to take
any of the following actions:
...
...
- use of any method, program, or device of any kind (including but not limited to GPS spoofing) to change or disguise the location of any device, your location, or the location of any other User"
If you are using a VPN, you are violating our Terms of Service, and your account is eligible for permanent deletion.