Enter Passcode for Other iPhone

Hello, I recently had to get my phone replaced and I am receiving an error when I try to turn on my iCloud Keychain:

"iCloud Keychain uses End-To-End Encryption Your Apple ID settings need to be updated so this Iphone can use end-to-end encyrption"

Then I click continue, enter my iphone passcode, then it brings me to a new screen that says "enter passcode for other iphone"

It only gives me the option to enter a 6 digit code, my previous iphone had an 8 digit code. When I click forgot password, I get a pop up that reads, "if you can't remember the passcode for iphone you can approve this iphone from another device signed into icloud"

I'm not seeing any where on my macbook or on icloud.com to approve the iphone. The only option I have is to reset encrypted data, which I don't want to do.

I have signed out of my apple ID on the iphone, reset the phone, and signed back in, but I am still getting still error, over and over.

Can you please help me???