How to download apk file of telegram app on android?
You can use the app APK Extractor to get the APK of the application you want on your device to send, or you can find a version of the app on a mirror site, like APKMirror.

I have used both in the past and have not had problems with them.

There are other apps similar to APK Extractor that allows you to obtain the APK, like Backup &amp; Restore. I have not used this one personally, but people have recommended it before.