Need advice on software integration! :)

Hi there!

I was wondering if anyone had any insight into how to best approach integrating with another software. Our company is a shift scheduling platform, for enterprise businesses. We are at a point where we need to integrate with Kronos (a payroll company).

I can't find any API documentation on their website and I was wondering if anyone had any insight on how to best move forward.

Do we need to apply to integrate with them? Do companies pay for this? Any insight would be helpful.

Thanks!