Could you please share a bit more about your scenario?
Do you want to use a 3rd party tool to Automate Testing for PowerApps app?
If you want to use a 3rd party tool to Automate Testing for PowerApps app, I afraid that there is no way to achieve your needs in PowerApps currently. Currently, there is no 3rd party Tool could be supported to run a PowerApps app.
PowerApps is a cloud service deployed in Azure, which has its own Running Platform. You could run a PowerApps app using web browser, Mobile device (Android device, iOS device and Windows phone) or Desktop Client.
More details about supported Platform to run PowerApps app and related limits, please check the following article: