@MoAmine
Please find this community post: Need help: Custom field (string) change history - #2 by lauma.cirule
It explains how to import custom fields with change history and how to use historical measures
Here is a documentation page on history measures:
https://docs.eazybi.com/eazybi/data-import/data-from-jira/import-issue-change-history#Importissuechangehistory-Customfieldchangehistory
But first, you would need to de-select it from the import options and import data without it to be able to override the data type from “text” to “string”
Martins / eazyBI