My client don't have Mobile studio but they need to send SMS from Marketing cloud. They have Long/Short codes purchased from third party providers not from Salesforce. As per my research we can achieve this by creating a custom activity but I have failed to create custom activity after multiple attempts. Later I came to know that we can send SMS with Code activity which was not available for my ORG. Can anybody help me how to send SMS from MC.
Unfortunately Code Activity for Journey Builder is in closed beta without ETA for open beta / GA.
Right now, apart from Mobile Connect, you have to use Custom Journey Activity. If your 3rd party SMS provider doesn't have one in AppExchange you can either code a custom for that specific 3rd party provider or leverage a pseudo-Code Activity described by @Sascha Huwald: https://www.linkedin.com/pulse/ssjs-journey-builder-sascha-huwald/
