for(Opportunity i : opProduct){

        pid.add(i.AccountId);
    }
        List<PriceBookEntry> priceBookList = [SELECT Id, Product2Id,Product2.Name FROM PriceBookEntry where Product2Id=:sub.OrderApi__Item__r.FS_Product__c];

        list<Opportunity> opo = [select id,name,closedate,AccountId,Pricebook2Id,StageName from Opportunity where AccountId in : pid];

        for(Opportunity pro : opo){

            if(pro.AccountId!=null){

                OpportunityLineItem l = new OpportunityLineItem(OpportunityId=pro.id,Quantity=1,UnitPrice=10,PricebookEntryId=priceBookList[0].Id,ServiceDate=system.today());
                li.add(l);
            }

        }
    }
    insert li;