Go to https://app.sweep.io/signup and enter email and password (or sign in with Google).
Verify your email from [email protected].
Follow the screens to connect your Salesforce environment (recommended to connect Production first).
While the initial connection is in progress, Install the Sweep Managed Package (select All Users).
After the Managed Package is installed (you’ll get an email) you can now assign the Sweep Permission Set Group to Salesforce users.
You can now connect the Sandbox(s), follow these Sandbox connection instructions..
Continue to install the Managed Package and assign the permission set as well.