Background:
At 3.28.10 I have installed the ESRI FileGDB driver, using the advanced OSGEO4W install. This allows me to write a vector layer to a new ESRI File Geodatabase (FGDB), using Export > Save Features As...
However, I am unable to write any additional layers to an existing FGDB because the Export dialog box does not allow me to enter the name of an existing FGDB. As a result, I am only able to create new FGDBs that contain just a single layer.
The Export dialog window has two options for saving to a FGDB, as shown in the screenshot:
ESRI File Geodatabase
ESRI FileGDB
Selecting either option results in the same single-layer FGDB output.
Question:
How to export additional layers to an existing File Geodatabase?

