How to glue two files .ogg (opus) using ffmpeg php exec?

Have 2 file a1.ogg and a2.ogg (codec OPUS)
Need to glue these files to new audio file
Trying to accomplish
exec ("ffmpeg -i 'concat:a1.ogg|a2.ogg' -c copy out.ogg",$output);

the file is not created
the result
array(0) { }

Checked the work on MP3 files, bonding didn't happen
exec('ffmpeg -i "concat:1.mp3|2.mp3" -c copy 3.mp3',$output);

The only thing that worked
$ ffmpeg -i input.mp4 output.avi

As found missing the opus codec in the ffmpeg build. And the original files in this format.
April 4th 20 at 13:29
0 answer

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