Upload 5mb/30mb file to Files not working

Hi all,
Using V12
ERPNext: v12.16.2 (version-12)

Frappe Framework: v12.13.0 (version-12)

Added on site_config.json “max_file_size”: 52428800 (50Mb)
but when uploading a file with 4Mb the below error message is returned:

Also changed the settings on nginx.conf
client_max_body_size 100M;

Any idea where to change so system allows to upload files ??