Can’t see my purchased ringtones from iTunes

If you have purchased ringtones, go to:

Settings → Sounds & Haptics → Ringtone → tap Download All Purchased Tones

The ringtones you purchased should download to your iPhone again. If your ringtones aren't downloading, it could be because the ringtones aren't available in iTunes anymore, or as SravanKrA suggests, you're not signed in with the Apple ID your ringtones were purchased through.

You can find more information at the bottom of this article:

Use tones and ringtones with your iPhone or iPad - Apple Support

If it is ringtones that you have purchased, then you must use the solution in my first answer. If the ringtones are ones you have downloaded yourself and imported into iTunes, then you must connect your iPhone and synchronize your ringtones with your iPhone. After that they should be available.

You can see how to sync your iPhone here:

Use iTunes to sync your iPhone, iPad, or iPod with your computer - Apple Support

Maybe you are not logged into iTunes with the correct Apple ID