Install a VPN. Be wary of those that claim to be totally free though; there are almost certainly some strings attached. Instead look for a provider that offers a free trial
TechRadar (which is well-respected) recommends ExpressVPN for Android phone users
https://www.techradar.com/uk/vpn/best-vpn-for-android-our-5-top-choices
and they offer a 30-day free trial:
https://www.expressvpn.com/features/vpn-trial
If the app needs to think that you're in another country when it's actually in use though (rather than just when you download and install it), you'll need to sign-up to a contract with a VPN provider.