Currently, Zeebe doesn’t support user tasks - in a way you might know from Camunda BPM 7. Zeebe has the concept of job workers. In your workflow, you model every task as service task and connect your applications for a specific type of tasks.
For example, you can define a task of type “user” and set properties like “formKey”. So, you can build a tasklist based on form.io. You can have a look at the community project Zeebe Simple Tasklist.
I don’t know form.io but I think that you could use the Node.js client to interact with Zeebe.