The Zoho integration isn't available as a workflow automation app, but I found two apps that connect the two systems and help automate processes: here.
I also wanted to ask other Community members if they have any advice:
Use Zoho Invoice integration in a workflow to update the Deal's value
We are only using Zoho Bigin, which has no integration with HubSpot. There might be some thing available via API's, but as I am not familiar with Zoho Invoice, i wouldn't be able to assist.