How can I assign permissions to existing roles?

Assigning permissions is possible, provided that you have a Manager Role. It is essential to consider that permissions are linked to the role (s) assigned to the user in question. Hence, to restrict access, the roles need to be modified. 

To modify the permissions assigned to a role, go through the following steps:

a) Go to Security>Roles, and then click on Permissions in the three dots menu on the right side of the screen.

b) Select the Module and Submodule where you need the permissions to be modified and either restrict it by clicking with a red cross or grant it with the blue checkmark