To enable the Zendesk integration inside HelpCenter.io, login to your help center dashboard and navigate to the settings pages:
Then, under Integrations, go ahead and enable the Zendesk integration by switching the toggle in front of the Zendesk logo on:
Take not of the subdomain and the Zendesk token that will appear as you will need these two in the next step.
Install our app in Zendesk
Next step is to go to the Zendesk marketplace and install the HelpCenter.io app:
https://www.zendesk.com/marketplace/apps/support/943718/helpcenterio/
When prompted, enter the subdomain you got from your help center dashboard into the Subdomain field in Zendesk, and the Zendesk Token into the Integration token field in the app installation screen.
Once done, scroll down until you find the "Install" button and press it. This will enable the HelpCenter.io app inside your Zendesk.