If self-employed can we claim The Sick-Leave Credit just by simply living in LA where there was strict quarantine rules in general?

Not just "by simply living" because of course you know how the quarantines affected daily living.  If you were unable to work or telework because of either the employee’s personal health status (that is, the employee is under COVID-19 quarantine or self-quarantine or has COVID-19 symptoms and is seeking a medical diagnosis) or the employee’s need to care for others (that is, the employee is caring for someone with COVID-19 or for a child whose school or place of care is closed or child care provider is unavailable), you can- and should- take the self-employed sick leave credit.