How can I convert OST files to PST format without losing data
You can convert OST files to PST format using the PDS OST to PST Converter. This professional software helps users recover inaccessible or orphaned OST files and convert them into PST format safely. It preserves email properties, attachments, and folder hierarchy while exporting data to Outlook PST.
https://apps.microsoft.com/detail/9p62fq9z8x7p?hl=en-US&gl=US
It is easy to convert OST file into PST file from online because there are multiple online converters available where you can easily convert your file free.