Add Harvest Button to Knack Application for tracking time

I have an Project Task tracking application built on Knack and am interesting in adding time-tracking via Harvest.

Harvest makes a button / widget for the purpose integrating with other applications.

Adding time tracking to your web application in 3 easy steps

The instruction is not really geared towards a no-code platform like Knack.

Has anyone attempted this in Knack or in the position to advise on whether this is possible by embedding the knack page into a web page and using JavaScript.

Many thanks

Adrian