Headless JS may be a solution https://reactnative.dev/docs/headless-js-android
hii Zacky Hotib,
if you can use javascript then just call cal nanoflow after page load and inside nanoflow call a javascript action
and in javascript we have setTimeout () method that can call you function when screen is lock of your PC
Window setTimeout() Method (w3schools.com)
I hope this will help you