There's a problem with the integration link given by Business Online Payroll (which is powered by Sure Payroll) for integrating with Zoho Books.

The link they give ends up with a Zoho Invalid Redirect URI error page that states "Redirect URI passed does not match with the one configured."

I suspect this is going to take collaboration between Zoho and Sure Payroll to fix.

Unfortunately, first-line support at both Zoho and Business Online Payroll just points fingers at the other company. This needs to be escalated to someone who knows what's going on and can work to get this fixed.