To Integrate the Slack account please use the following steps.
Click on Slack Integration Card or the ‘Connect’ button.
Click on the "Login to Slack" button on the next page.
You will be redirected to a Slack connection page.
If you want to change the workspace, it can be changed on the top-right corner of the page.
After that, click "Allow" to grant the permissions needed for the Slack app.
On the next page, select the channel you want to receive your notifications on from the dropdown menu and press "Continue".
Now you have successfully connected your neetoCal account with your Slack account and will be redirected to the integration page.