iPhone XR speaker not work after instal ios 14.8

Try these tips first:

If you can't hear any sound or hear distorted sound from your iPhone, iPad or iPod touch speaker - Apple Official Support

If those tips didn’t solve the problem, you should backup and restore your iPhone:

Back up iPhone - iPhone User Guide - Apple Official Support

Restore your iPhone, iPad or iPod touch from a backup - Apple Official Support

And if those tips didn't work either.... You should contact Apple Support in order to receive more information on what to do next:

Contact Apple Support - Apple Official Support