@David Zhu , Thanks for the refernce. I wrote the below piece of code as suggested but getting the below error so can you please help me out to resolve the error.

Error:Apex trigger QuoteLineItem caused an unexpected exception, contact your administrator: QuoteLineItem: execution of AfterUpdate caused by: System.SObjectException: Invalid field Quote.opportunityId for AggregateResult: Trigger.QuoteLineItem: line 21, column 1

trigger QuoteLineItem on QuoteLineItem (after insert, after update) {
    set<id> quoteIdset =new set<id>();
    
    for(QuoteLineItem qol:trigger.new){
        quoteIdset.add(qol.Quoteid); //quoteId
    }
    
    List<opportunity> oppListtoUpdt=new list<opportunity>();
    set<id> oppIdSet=new set<id>();
    
    map<id,Quote> mapofQuote=new map<id,Quote>([select id,opportunityid from Quote where id=:quoteIdset]);
    
    for(Quote quoteRec:mapofQuote.values()){
        oppIdSet.add(quoteRec.opportunityid);
    }
    
    Map<ID, opportunity> mapOppty = new Map<ID, opportunity>([select id,Gross_Amount__c from opportunity where id=:oppIdSet]);
    AggregateResult[] groupedResults = [SELECT Quote.opportunityId,SUM(Amount__c)amt FROM 
                                        QuoteLineItem where Quote.opportunityId in:oppIdSet group by Quote.opportunityId];
    for(AggregateResult Results: groupedResults){
        Id opptyId =(id) Results.get('Quote.opportunityId');
        Opportunity opp=mapOppty.get(opptyId);
        opp.Gross_Amount__c=(integer)Results.get('amt');
        oppListtoUpdt.add(opp);
    }
    update oppListtoUpdt;
}