Making a Tiktok ringtone on an iPhone is possible by using the built-in GarageBand app. First, open GarageBand and create a new project. Next, tap on the loop icon in the top-right corner and search for the Tiktok sound you want to use. Once you have found it, drag it onto the timeline.
You can then edit the sound by trimming the length to the desired duration and adjusting the volume levels. Once you're happy, tap on the share icon and select "Ringtone". You can then name the ringtone and choose to export it to your iPhone's ringtone library.
Finally, go to your iPhone's settings and under the "Sounds & Haptics" menu, select "Ringtone". You should see your new Tiktok ringtone listed as an option which you can set as your default ringtone or assign to individual contacts.