Auto update to latest build on playstore or app store without uploading with new verion

Hello Sir,
We have created one application with v1.0.2 and uploaded on play store and app store.
After that we were working on new feature for similar app and created .apk and .ipa for testing purpose but got to know that latest changes are getting reflected on playstore as well as app store.
Now, we understand that apk is using latest build from expo website but how, and why? we dont understand the logic behind it.

When you run expo build:android or expo build:ios command there is also publish triggered internally.

When you want to build apk or ipa to test locally use different release channel or build with --no-publish. Be carfull with the flag --no-publish, build using taht flag will use last published js bundle not your current sources.