If you want to use this plugin for bus ticket selling but default there is no label, you can change the label globally.

Go to Settings-> Bus Settings and change the Bus Label and Bus Slug field to any name you want.

If you want to add icon, you need to select from the dashicons library.

how to change the label of bus

Then click on the Save Changes button.

Also you can change the label from Quick Setup -> Click Next -> Next -> General

After Save Changes, you have to update the permalink from here Settings->Permalink and hit the Save Settings button.