How to default rate type in AR at Invoice level?

Summary: Hi Team,

We have multiple BU's out of which for 1 BU, we are having requirement to default conversion rate type in AR at Invoice level.

For remaining BU's, we are using 'Corporate' rate but for this particular BU requirement is different.

Can anybody suggest if we have any setup for this?

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable): 24D (11.13.24.10.0)

Code Snippet (add any code snippets that support your topic, if applicable):