How to Customise Fusion to Remove the Complete Button in the Billing Workarea?

Summary

The current issue is that we need a role/user level customisation to remove the "Complete" Button which is present in the Billing Work Area. The End Goal is to have a Data Entry User in Billing

Content

Problem Summary
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Customise Fusion - How to cusotmise Fusion on a User Level so a User can come into Fusion an a section is removed/made unclickable.

Problem Description
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We are currently facing an issue with a user will be an external user to the finance team but is only required to Create A Transaction from within Billing. Currently this is working well but I wanted to seek advice on how to proceed with this further so that the User cannot click Complete.