Unable to add condition 'category' in promote so spend authorized approval flow

Summary

Unable to add condition 'category' in promote so spend authorized approval flow

Content

We want to be able to add the condition 'category' in the spend authorization approval flow, but this option does not exist. I am also not able to add a user managed attribute. In the register (and internally register) supplier flow i am allowed to add the category condition, why the difference?

Thank you

Jasper Oskam