How do I set up voicemail or an iPhone 7 Plus without using a password
How do I set up voicemail on an iPhone 7 Plus without using a password
Question marked as
That would be a question you would need to ask your carrier. Voicemail is a carrier feature, and the carrier controls it. You may not realize it, but you have always had a password for your voicemail to prevent unauthorized access to the account. If you need help with resetting it, your carrier can take are of that for you.