How to export a layout to GeoPDF format using QGIS on Ubuntu 20.04?

I’d like to export a layout in GeoPDF format using QGIS 3.12.3-București (1:3.12.3+32focal) installed on Ubuntu 20.04 Focal Fossa from https://qgis.org/ubuntu repository.

QGIS is compiled and runs against GDAL/OGR 3.0.4 (3.0.4+dfsg-1build3).

The poppler library (libpoppler97 0.86.1-0ubuntu1) is installed with the following packages:

• libpoppler-cpp0v5/focal,now 0.86.1-0ubuntu1 amd64
• libpoppler-dev/focal,now 0.86.1-0ubuntu1 amd64
• libpoppler-glib8/focal,now 0.86.1-0ubuntu1 amd64
• libpoppler-private-dev/focal,now 0.86.1-0ubuntu1 amd64
• libpoppler97/focal,now 0.86.1-0ubuntu1 amd64
• poppler-data/focal,focal,now 0.4.9-2 all
• poppler-utils/focal,now 0.86.1-0ubuntu1 amd64

Both

gdalinfo --formats | grep -i pdf

and

ogrinfo --formats | grep -i pdf

output:

PDF -raster,vector- (rw+vs): Geospatial PDF

However, the "Create Geospatial PDF (GeoPDF)" checkbox is disabled in the PDF Export Options window with the following explanation:
"GDAL PDF driver was not built with PDF read support. A build with PDF read support is required for GeoPDF creation."

What else should I do and what other package should I install in order to enable the GeoPDF exporting feature?