I am trying to assign an Business account to an user and not able to figure out how to do it.
I believe you are trying to customize Catalog form (SP700000) on Acumatica Portal site and getting Your user profile is not associated with any Business Account message.
Associated business account check is done in constructor of the InventoryLineMaint Graph linked to this page and if not found; exception is raised which is correct by design. And that’s the reason you are seeing this message.
To customize this screen using Acumatica Customization Browser, you should create an admin Portal user who is associated with business account. Allow roles Customizer and Portal Admin for External User Type. You need to check Guest Role for these two in order to add here.
Step # 1
Login to ERP using admin credential, navigate to User Roles screen (SM201005), and check Guest Role for Customizer and Portal Admin roles in order to add them on EP202500.
Step # 2
Now navigate to User Types screen (EP202500), and select External User Type. Modify to allow roles Customizer and Portal Admin for External User Type.
Step # 3
Now create External user.
Navigate to Customers Screen (AR303000) and select ABARTENDE customer. Go to Contacts tab and open up existing Contact - Kabuk Fadi, Mr. (CR302000) Navigate to User Info tab and setup External user as below.
Step # 4
Now login to Portal site using this user. You should be able to customize page SP700000 via Acumatica Customization Browser.