(Note: Before you upload, it's great to check out our help article Useful tips before your asset upload if you haven't already)
Simply drag and drop the file(s) into the browser or click the Upload New button to upload file(s) using a file browser dialog. Be sure to include the asset’s texture(s) and other associated files (e.g., *.mtl material file for OBJ if available). You can optionally include photos and camera position data (e.g., csv or xml). Upload progress will be displayed within the “Upload Jobs” tab.
For more information about how Nira automatically classifies images as either photos or textures, see this related article: https://help.nira.app/hc/en-us/articles/4418127878811
To learn how to upload additional files to an existing asset, see: How can I upload additional files to an existing asset?