challenge-4.cls

public class ProjectCalloutService {
    //Complete the implementation for business and callout logic
    @InvocableMethod(label='Make REST Callout' description='Inserts' category= 'Opportunity')
	public static void PostOpportunityToPMS(List<id> opId){
        Opportunity opp = [
            select id, name, Account.Name, closeDate, amount, StageName  
            from Opportunity
            where id =: opId[0]]; 
        ID jobID = System.enqueueJob(new QueueablePMSCall(opp));
    }

    public class QueueablePMSCall implements System.Queueable, Database.AllowsCallouts {
        private String jsonBody;
        
        private Opportunity opp;
        

        public QueueablePMSCall(Opportunity oppObj){
            opp = oppObj;
            JSONGenerator gen = JSON.createGenerator(true);
            gen.writeStartObject();
            gen.writeStringField('opportunityId', opp.Id);
            gen.writeStringField('opportunityName', opp.Name);
            gen.writeStringField('accountName', opp.account.Name);
            gen.writeDateField('closeDate', opp.closeDate);
            gen.writeNumberField('amount', opp.amount);
            gen.writeEndObject();            
            
            jsonBody = gen.getAsString();
        }
        
        public void execute(QueueableContext context) {
            //List<ServiceTokens_c> mcs = ServiceTokens_c.getall().values();
            ServiceTokens__c token = ServiceTokens__c.getValues('ProjectServiceToken');

            Http http = new Http();
            HttpRequest request = new HttpRequest();

            request.setEndpoint('callout:ProjectService/'+ token.Token__c);
            //request.setEndpoint('https://sb-integration-pms-2.herokuapp.com/projects');
            request.setMethod('POST');
            request.setHeader('token', token.Token__c);
            request.setHeader('Content-Type', 'application/json;charset=UTF-8');
            // Set the body as a JSON object
            
            request.setBody(jsonBody);
            HttpResponse response = http.send(request);
            // Parse the JSON response
            if(response.getStatusCode() == 201) {
                opp.StageName = 'Submitted Project';
                update opp;
            } else if(response.getStatusCode() == 500) {
                opp.StageName = 'Resubmit Project';
                update opp;
            }
        }
    }
}