As explained in the article "How to add drivers" you can add new drivers through My Hub and create their profile manually.
You can also allow your drivers to register through their apps. For that open My Hub, choose tab "Drivers management", find "Driver settings" in the top right corner of the screen and tick "Allow signup via driver app".
Now your drivers will be able to send their requests for activation through their driver app.
Once the driver downloads the driver app he will have to sign in and fill in all the requested info to be sent to the company he wants to join. Having submitted the request for activation he will see the following:
Now that the driver's request has been submitted the request has to be accepted and processed following the next steps:
a. Go to the tab "Drivers" in My Hub and filter drivers by "Waiting for activation status".
b. After that press on the driver's name to open their profile. Review the information the driver provided and add the driver's service type from the drop down list "Service type" change profile status from "Waiting for activation" to "Active" and press on "SAVE" button.
с. Now the driver's "Activation request" has been processed, so, the driver can enter his app and start his first shift.
All done! Your driver's request for activation has been successfully processed and you have a new member of your fleet now.