Overriding Indigo Theme

Hi I am new to open edx platform, Want to override or create my own stylesheet in the indigo theme that I clone here GitHub - overhangio/tutor-indigo: An elegant, customizable theme for Open edX and I follow the instructions, I also try to edit the _extras.scss in here and do the local images build openedx followed by tutor local start -d \tutor\env\build\openedx\themes\indigo\lms\static\sass\partials\lms\theme but still has no effect. can someone help me to edit the styles ?

thank you