To transfer any file from iPhone to Android without app is very easy you just have to follow these steps to transfer a file

Transfer via Cable: What do you have to do you just have to connect the compatible cable like type c to type c  

After connecting both the devices through wire now verify the connection on your iPhone and Android and Grand permission to transfer the file

Android File Access: Now you can easily access iPhone storage on your Android device through cable in high speed.

Select and Transfer Files: After connecting, Now you can choose a specific file to transfer from iPhone to Android

iCloud: This method of transferring files needs an internet connection to upload photos/videos to iCloud on iPhone.

Android iCloud App: On an Android device you have to download and install the iCloud app then only you can able to download the file

Sign in to iCloud: now login to iCloud storage from the Android app and access the uploaded file on your Android device.

Download Specific Photos/Videos: If you have a good connection to the internet then you can download photos and videos to your Android device easily