add_one() {
 ACCESS_TOKEN="$(./3_gCal_access_token.sh)"
 CAL_ID="$(get_calID_byName "$ACCESS_TOKEN" 'testDB')"
 EVENT_INSERT_ENDPOINT="https://www.googleapis.com/calendar/v3/calendars/${CAL_ID}/events"

 SUMMARY="$1"
 START_TIME="$2"
 END_TIME="$3"

 TIMEZONE="Asia/Taipei"     # required

 JSON_BODY="$(
    jq -n \
       --arg summary "$SUMMARY" \
       --arg st "$START_TIME" \
       --arg et "$END_TIME" \
       --arg tz "$TIMEZONE" \
       '{
           summary: $summary,
           start: { dateTime: $st, timeZone: $tz },
           end:   { dateTime: $et, timeZone: $tz }
        }'
 )"

 RESULT="$(
    curl -sS -X POST "$EVENT_INSERT_ENDPOINT" \
        -H "Authorization: Bearer $ACCESS_TOKEN" \
        -H "Content-Type: application/json" \
        -d "$JSON_BODY"
 )"

 echo $RESULT
}