Symfony plural form is not recognized when upload

[patckin-d]

Hello! I tried to make a script to upload translations from code into Lokalise. I faced issue when I try to upload plural key in Symphony format.
I try to upload key { "plural_gitlab": "p4|p44" }
And I got

But I expected to have:

In project settings I set JSON import format to Classic

My script:

#!/bin/bash
set -euo pipefail

: "${LOKALISE_API_TOKEN:?Need to set LOKALISE_API_TOKEN}"
: "${LOKALISE_PROJECT_ID:?Need to set LOKALISE_PROJECT_ID}"

BIN_DIR="./bin"
LOKALISE_CLI="$BIN_DIR/lokalise2"
BRANCH_TAG="gitlab-integration-test"

if [[ ! -x "$LOKALISE_CLI" ]]; then
  echo "❌ Lokalise CLI not found $LOKALISE_CLI"
  exit 1
fi

if [[ ! -d "locales/en" ]]; then
  echo "❌ Directory 'locales/en' not found!"
  exit 1
fi

echo "🚀 Uploading from locales/en/..."
echo "📛 Using tag: $BRANCH_TAG"

find locales/en -name '*.json' | xargs -P 6 -I{} env FILE="{}" BRANCH_TAG="$BRANCH_TAG" bash -c '
  echo "📤 Uploading $FILE..."
  '"$LOKALISE_CLI"' \
    --token='"$LOKALISE_API_TOKEN"' \
    --project-id='"$LOKALISE_PROJECT_ID"' \
    file upload \
    --file="$FILE" \
    --lang-iso="en" \
    --convert-placeholders='false' \
    --detect-icu-plurals='true' \
    --include-path \
    --replace-modified \
    --poll \
    --tag-inserted-keys \
    --tags="gitlab,$BRANCH_TAG"
  echo "✅ Uploaded: $FILE"

'

echo "🎉 All files uploaded."

I didn't find a flag to set plural format on upload, may be I need to configure anything in my project that I have no permission? Please, help