how can I find all iCloud emails under my phone number?

Once Apple ID is signed in with its password in iPhone and mail box is turned as on https://support.apple.com/en-us/HT207689

The mails can be searched see the article https://support.apple.com/en-us/HT207132

https://support.apple.com/guide/iphone/search-for-email-iphb2eab8035/ios

What do you mean "under my phone number"? How exactly are you accessing your emails?