If the SQL Insight monitor is not getting added even after entering your credentials, try these troubleshooting steps:
Ensure that the Auto-discover applications feature is enabled. If not, you will need to trigger discovery using the Discover Applications tab from the corresponding server monitor after giving your credentials. (Server > Server Monitors > Servers > Click the desired monitor > Click the hamburger icon beside the monitor name > Discover Applications)
If you have an SQL cluster setup, you need to give the credentials in both the active and passive nodes, as both the nodes will point to a single Insight monitor in the Site24x7 web console.
Check if FIPS has been enabled in the machine by checking the below registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Lsa\FipsAlgorithmPolicy\Enabled
If FIPS has been enabled, kindly contact our support team for assistance.
Also, ensure that the credentials given are valid and that you're able to log in to your SQL instance with the same credentials.