Navigate to Traffic Managment on the side tab bar

Select WTMP on the top tab bar

Select the WTMP you want to add a permit too

Scroll down in the overview of the works to the Required Permits section

+New

Select Works Revision from drop-down

Select Permit Issuer from the drop-down. Or select the + to create a new permit issuer

Create

Choose a permit from the Attach Permit drop-down. Alternatively, press the + button to create a new permit to attach

Check Permit details

Save