Schema.org issues

[malikwalodat]

Recently we have added our store to google search console, after days google search console said that our store has issues and warnings like " Incorrect value type "," The brand field is recommended. Please provide a value if available. " and " This product is missing a global identifier (e.g. isbn, mpn or gtin8). Please see documentation for valid identifiers. " can you help me to fix these issues and warnings.