Problems on MacOs - PLEASE HELP

[paoang]

Hi,
I'm completely unexperienced with terminal.
I just installed plotman and configured the plotman.yaml.

but when I try to plot it writes the following:

Paolos-iMac:~ paolo$ plotman plot
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.9/bin/plotman", line 8, in
sys.exit(main())
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/plotman/plotman.py", line 137, in main
cfg = configuration.get_validated_configs(config_text, config_path)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/plotman/configuration.py", line 37, in get_validated_configs
config_objects = yaml.load(config_text, Loader=yaml.SafeLoader)
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/yaml/init.py", line 114, in load
return loader.get_single_data()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/yaml/constructor.py", line 49, in get_single_data
node = self.get_single_node()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/yaml/composer.py", line 39, in get_single_node
if not self.check_event(StreamEndEvent):
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/yaml/parser.py", line 98, in check_event
self.current_event = self.state()
File "/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/yaml/parser.py", line 171, in parse_document_start
raise ParserError(None, None,
yaml.parser.ParserError: expected '', but found ''
in "", line 4, column 1:
user_interface:
^
Paolos-iMac:~ paolo$

How can I solve this?