Slack (SaaS)integration URL cannot installed at this URL in servicenow.

[rohanchouhan22]

Hi Team,

Please find the attached screenshot of the error.

[Sohail Khilji]

Hi @rohanchouhan22 ,

have a check in the URL which you tried. Make sure to use naked url without any path...

OR 

The url that your using may not be allowed by slack application {blacklisted URL}

i hope this helps...