I get the error, "I'm sorry, but you are not authorized to install Askdata."
Slack guest users
Note that Slack guest users aren't able to install apps. As a Slack guest user, you can send a direct message to @Askdata within Slack, with just the word login
Askdata will then send you a link that you can use once logged in.
How to login without using the "Login with Slack" button
You can always login by sending a direct message to @Askdata, inside Slack.
To do this, send a direct message to @Askdata within Slack, with just the word login
How to pre-approve Askdata to work with everybody in your team
Depending on the way that Slack is configured, it's possible that Askdata may need to be approved by a team administrator or the team owner.
To pre-approve Askdata to work with your team, you can visit http://slack.com/apps/manage and click the "Approve" button beside Teamline. This will allow your team members to login and use Askdata.