Unhandled exception (#71ac61ae)

[sqlmapreporter]

Running version: 1.8.6.9#dev
Python version: 2.7.14
Operating system: Windows-10-10.0.20348
Command line: sqlmap.py -u ************************************************** -p cate_id --batch --random-agent --risk=3 --level=5 --threads=10 --technique=UE
Technique: None
Back-end DBMS: None

Traceback (most recent call last):
  File "sqlmap.py", line 188, in main
    from lib.controller.controller import start
  File "lib/controller/controller.py", line 78, in <module>
    from lib.core.target import initTargetEnv
  File "lib/core/target.py", line 41, in <module>
    from lib.core.dump import dumper
  File "lib/core/dump.py", line 244
    full_url = f"{api_url}?{query_string}"
                                         ^
SyntaxError: invalid syntax