fix: AWSAppSyncRealTimeProvider websocket init fix (#9200)

packages/pubsub/src/Providers/AWSAppSyncRealTimeProvider.ts

@@ -600,11 +600,6 @@ export class AWSAppSyncRealTimeProvider extends AbstractPubSubProvider {
 			if (this.socketStatus === SOCKET_STATUS.CLOSED) {
 				try {
 					this.socketStatus = SOCKET_STATUS.CONNECTING;
-					// Creating websocket url with required query strings
-					const protocol = this.isSSLEnabled ? 'wss://' : 'ws://';
-					let discoverableEndpoint: string = appSyncGraphqlEndpoint
-						.replace('https://', protocol)
-						.replace('http://', protocol);
 
 					const payloadString = '{}';
 					const headerString = JSON.stringify(
@@ -622,6 +617,8 @@ export class AWSAppSyncRealTimeProvider extends AbstractPubSubProvider {
 
 					const payloadQs = Buffer.from(payloadString).toString('base64');
 
+					let discoverableEndpoint = appSyncGraphqlEndpoint;
+
 					if (this.isCustomDomain(discoverableEndpoint)) {
 						discoverableEndpoint = discoverableEndpoint.concat(
 							customDomainPath
@@ -630,6 +627,12 @@ export class AWSAppSyncRealTimeProvider extends AbstractPubSubProvider {
 						discoverableEndpoint = discoverableEndpoint.replace('appsync-api', 'appsync-realtime-api').replace('gogi-beta', 'grt-beta');
 					}
 
+				    // Creating websocket url with required query strings
+					const protocol = this.isSSLEnabled ? 'wss://' : 'ws://';
+					discoverableEndpoint = discoverableEndpoint
+						.replace('https://', protocol)
+						.replace('http://', protocol);
+
 					const awsRealTimeUrl = `${discoverableEndpoint}?header=${headerQs}&payload=${payloadQs}`;
 
 					await this._initializeRetryableHandshake({ awsRealTimeUrl });