Log in to Coupa as an 'integrations enabled' administrator and go to: Setup > Oauth2/OpenID Connect Clients.
Type 'oauth' into the search box to find the page quickly.
For Grant Type select: Client credentials.
Specify a Name for the Client (we recommend 'Trelica integration').
Enter Login, Contact info, and Contact Email. Login is just text (you can enter 'Client'). The contact details are simply so that other Coupa administrators know who configured the connection, so we recommend entering your name and email.
Select the following Scopes:
Click on Save.
Saving the client gives you values of the client Identifier and Secret which you will need to enter into Trelica.
Click Show/Hide to display and copy the Secret.