Once the list of STAC collections is displayed in the Explore STAC pane, you can click the Select assets button 
in the Search Collections list on the Parameters tab, to open the Select assets dialog box.
Use the check boxes at the bottom of the Select assets dialog box to work with the assets you select:
- Create multiband raster from selected asset types—Create a multiband raster from the selected assets. This option is enabled only if you select two or more assets.
- Ignore missing assets when creating multiband raster—Ignore datasets with missing assets when they are used in ArcGIS Pro. Checking this option is useful when a large number of datasets are added to a map, scene, or mosaic dataset.
Note:
Select Raster Dataset as the Raster Type parameter value when adding the selected assets to a mosaic dataset using the Add Rasters to Mosaic Dataset tool.