invok integration from applications field

Summary:

we have argent issue to validate field on specific application page to prevent duplication for this field value it should be unique(like employee IBAN in Hcm should be unique) ,we thinking for work around that create integration that call Bi to check if the value exist before ,then invoke the integration on that field, is there any suggetion.

or different approche to achive this validation

Content (please ensure you mask any confidential information):

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

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