Then all you need to do is click Test connection.
After you click Test connection, a browser should pop up.
After the successful login, you need to authorize ManicTime access to Harvest.
If authorization was successful, you should see this message.
Back to ManicTime, where connection window should update with additional settings, where you can choose projects which will show up as tags in ManicTime.
We suggest you prefix tags coming Harvest with "Harvest" tag, so you can later identify them in Add tag window. Tags from Harvest will look like:
<any preceding tag you defined>, Project from Harvest [Project Id], Task [Task Id]
Then open Add tag window and type Harvest in tag field to filter by Harvest. Create a tag.
Then go to plugins -> Tasks from Harvest -> Save work
This will send tags you created in ManicTime back to Harvest.