Problem with pass CIRCLE_BRANCH variable to POST body

API
3

Unfortunately, the problem is not solved. It worked fine but now when I call this from branch_name = feature/B1

if [ "$CIRCLE_BRANCH" = "develop" ] || [ "$CIRCLE_BRANCH" = "feature/B1" ]; then

    curl -X POST \
    --header "Circle-Token: $CIRCLECI_API_TOKEN" \
    --header "Content-Type: application/x-www-form-urlencoded" \
    --url https://circleci.com/api/v2/project/bitbucket/......... \
    -d "branch: $CIRCLE_BRANCH"    <----- **develop branch is called here, i do not have develop now**

fi

echo $CIRCLE_BRANCH returns feature/B1 , but why in curl I see develop ??