If you use Clik Service and integrate with Xero Accounts, you must update the certificate used to integrate the software before 17th July 2018.
To do this you will need to first update Clik Service to build 321.
Once updated, log into Clik Service with appropriate administrator settings and ensure it has been updated to build 321. You can double-check this by going to Help > About from the top menu
Next click on Settings > Settings > Accounts from the top menu.
Ensure that 'Enable accounts integration' is ticked and set to "Xero" and correct integration details are already inserted. Click on 'v2 (expires 28/5/2023)' and then 'Export public key'.
This will export the new certificate out of Clik Service ready to be uploaded into your Xero settings. Give the certificate a filename and save.
Now login into https://app.xero.com/ using your Xero credentials.
Once you are logged in click on 'My Apps'.
You will see an app listed below for integration between Clik Service & Xero. Click on this to load up the app details.
At the bottom of the page, you should see a section called 'Public key certificate'. Below this, is an expiry date which will show as below:
Now click on 'Update Public Key' and either select or drag the exported certificate from Clik Service into this window. Then click on 'Update' and the expires date should now be set to 2023-05-28.