How to extend BI Publisher report to xlsx

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I am running a report that exceeds 65531 rows, I read in the documentation that we can extend this format from XLS to XLSX which guarantees us approximately 1,000,000 rows.

I am running a report that exceeds 65531 rows. I read in the documentation that we can extend this format from XLS to XLSX, which guarantees approximately 1,000,000 rows.

I enabled Scalable Mode, but the XLSX option is not available.

I am using a BI Publisher template report.

What is the best recommendation so that I do not have a multisheet result as an output due to the limit?