CLI: {title} and {group} does not give correct result

Hi, the following CLI does not give me what I expect.

-b MyFile.ase --save-as="{title}_{group}_{frame}_{tag}_{tagframe}.png"

The result is:
{title}_MyGroup__MyTag__MyFirstGroup_0_MyFirstTag_0.png {title}_MyGroup__MyTag__MyFirstGroup_1_MySecondTag_1.png {title}_MyGroup__MyTag__MySecondGroup_0_MyFirstTag_0.png {title}_MyGroup__MyTag__MySecondGroup_1_MySecondTag_1.png

What I expect is:
MyFile_MyFirstGroup_0_MyFirstTag_0.png MyFile_MyFirstGroup_1_MySecondTag_0.png MyFile_MySecondGroup_0_MyFirstTag_0.png MyFile_MySecondGroup_1_MySecondTag_0.png

Am I doing something wrong?

The full script (using Mac OS automator) is this:
for f in "$@"; do
FILE="$f"
cd "$(dirname "$f")"
mkdir "Exported Frames"
~/Library/"Application Support"/Steam/steamapps/common/Aseprite/Aseprite.app/Contents/MacOS/aseprite -b "$FILE" --save-as="$(dirname "$f")/Exported Frames/{title}_{group}_{frame}_{tag}_{tagframe}.png"
done