Export an image with Adobe Lightroom in PNG format can be very useful because with this format you don't loose a lot of detail in the outlines. In addition, the compression algorithms of the social networks that disfigure the photographs compress very the JPEG file. In fact, if you upload a high-resolution photo in JPEG format and a picture in PNG format you'll notice the difference immediately in terms of quality. The PNG is better, but weighs more, however, because the JPEG format is much more efficient in terms of file size.
There are plugins in Adobe Lightroom that allow you to export your files in PNG format. The plugin which we'll talk about today is called Magic Export for Lightroom and is available for download at this address.
After the download of the zip file you have to unzip it. At this point, you should have a folder called MagicExport_v0.5. Inside this folder you will find another one that is called Magic Export.lrplugin
This is the folder of the plugin that interests us. The next step is to add the plugin in the program Adobe Lightroom. You have to open the program and export an image to open the export window.
To use this plugin is certainly not intuitive, I suggest you follow the next steps of the guide to Export an image with Adobe Lightroom in PNG format. You need to choose "Magic Export" from the dropdown menu. You will notice on the right that something has changed. In the final part of the window, at the bottom you will see the box Magic Export. Here in the drop-down menu, choose PNG. On the right you can also specify the resolution. At this point click on "Export" and at the end of the process, the PNG file will be exported to the destination folder that you chose in the same window.
I also created an instructional video accessible on this link.