Convert xls files to csv files in apache NIFI

[#1]

Hello guys I'm trying to convert .xls files to .csv in apache NIFI data flow. I tried many solutions with no result I even tried creating a script like this sccript

Thank you in advance

[#2]

most file formats can be extracted via tika

https://community.cloudera.com/t5/Community-Articles/ExtractText-NiFi-Custom-Processor-Powered-by-Ap...