How to run Nodejs runtime on android or ios mobile devices

You can use JXCore to run Node.js with Express on mobile devices with PhoneGap, here is a link of a tutorial and more details about JXCore: https://www.sitepoint.com/how-to-run-node-js-with-express-on-mobile-devices/

You can use Node.js for Mobile Apps.

At its core, the project provides a native library for embedding Node.js into native Android and iOS applications; but it also comes with plugins for React Native and Cordova.

Pre-built binaries for the library are available for Android armeabi-v7a, x86, arm64-v8a, x86_64, and for iOS 64-bit.

More information, including some documentation, is available on the project website.

(Full disclosure: I work for the company that develops Node.js for Mobile Apps.)