Xero has a great feature where you can get the Public URL of an Invoice if you are logged into Xero. To see the public URL, in Xero, click the arrow by Invoice Options (on the upper right of an Invoice page) then "Share Invoice". Xero will generate a public URL.
At Breadwinner, we would love to provide this Share Invoice / Public Invoice URL to you.
However, Breadwinner communicates with Xero through Xero's API, and currently there is no functional way for us to get this public URL.
If you need this feature, then you can help by voting in Xero's feature request forum and adding your voice to all the other Xero Users that need this feature. You can vote using the link below:
Once Xero enables this feature (it could be years, as it's been 3 years already since I posted this feature request) we will happily build this feature into Breadwinner.