I am running the below code in developer console to get OrgPercentage coverage, but it is throwing an error
"errorCode":"METHOD_NOT_ALLOWED","message":"HTTP Method 'POST' not allowed. Allowed are HEAD,GET"
I am using "GET" method in my code. I am not sure where POST is happening
HttpRequest reqOrgCoverage = new HttpRequest();
String ClientId = 'XXXXXXXXXXXXXXXXXXXXXXXXXXX';
String ClientSecret = 'XXXXXXXXXXXXXXXXXXXXXXXX';
String redirectUrl = 'test.salesforce.com';
//reqOrgCoverage.setHeader('Authorization', 'OAuth' + UserInfo.getSessionID());
reqOrgCoverage.setHeader('Authorization', 'Bearer ' + UserInfo.getSessionID());
reqOrgCoverage.setHeader('Content-Type', 'application/json');
reqOrgCoverage.setBody('grant_type=authorization_code' +
'&client_id=' + ClientId +
'&client_secret=' + ClientSecret +
'&redirect_uri='+redirectUrl);
reqOrgCoverage.setEndpoint(URL.getSalesforceBaseURL().toExternalForm()+'/services/data/v43.0/tooling/query/?q=Select+PercentCovered+from+ApexOrgWideCoverage');
reqOrgCoverage.setMethod('GET');
Http h = new Http();
HttpResponse resHttp = h.send(reqOrgCoverage);
System.debug('response: ' + resHttp.getBody());