voicemail is not working on my iphone 8

Hello Collegestation2019 and welcome to Apple Support Communities.

It appears you're having some issues with the Visual Voicemail feature on your iPhone.

Start by making sure you are on the most current iOS version (13.1.1 at the time of this message).

Update your iPhone, iPad, or iPod touch - Apple Support

If that does not resolve this, then double check that there is not an update specific to your carrier.

Update your carrier settings on your iPhone or iPad - Apple Support

Next, ensure that your carrier supports Visual Voicemail

Wireless carrier support and features for iPhone in the United States and Canada - Apple Support

If they support the feature, try the steps here under the section called Get help with Visual Voicemail

Set up Visual Voicemail on your iPhone - Apple Support

If the issue remains unresolved, you'll want to reach out to your carrier.

Cheers.