Click on Options
Select Show, next to Roles.
Select the desired role you want to delete from the drop-down list.
Tap on the selected role name, click on the three dots next to the name, and then click on Delete.
A pop-up will appear to confirm the action. Click Yes.
The role will disappear from the Roles page.
Disclaimer: make sure you want to delete the role because it can't be restored.