How to set a user role when creating a user?

I have created a Webform Content Creator entity to create a user on a webform submission. As part of the creation process, I would like to set a user role I created called "Profile pending" which has the machine name "profile_pending".

In the managed fields, I tried to set the "Roles" field by enabling "Custom" and by entering the machine name of my user role "profile_pending" (see attached jpg) however the role does not get set...

Would anyone know what I did wrong and how I should set the role?

Thank you for your assistance in this matter.