...
It is necessary to create a new consumer key for the connection between Magento 2 and Xero.
First of all, go to https://www.xero.com/ and register an Xero accounts (click on "Try xero for free" or "Free Trial"). If you already have an account, you can skip this step.
...
Set up Xero Account Informations
At My Applications tab
First, it is necessary for you to set up the connection between Magento 2 store and Xero. Getting Consumer Key from Xero Taking Consumer Key that you have just created and paste into Magento 2 backend configuration. Then, click on Connect Now button.
Connection Status will be transferred from not connected to connected with all the information like the picture below.
Press Save Config after you've done (refresh the cache if needed).
At Configure the Accounts Types in Xero tab
Admins are able to synchronize four account types: Bank account, Sale account, Inventory account, Cost and Good Sold account from Magento 2 to Xero.
Enter name for each account then click on Sync All Accounts Now button. The default Xero account value will be used if you do not change it. If there is no account on Xero site, the extension will automatically create a new one.
Set up Synchronization
...