ALM license usage

Hello everyone, 

Hope you are doing well.

I have a confusing question, and I hope you can help me answer because I am quite new to this.

 - my customer is intending to use Synchronizer to synchronize 2 instances of HP-ALM.

- The first ALM is SopraSteria ALM with SopraSteria licenses, the second ALM is Customer ALM with customer licenses. Synchronizer would be on Customer side.

- They also have to create an account on SopraSteria ALM for Synchronizer access.

The question is if we need any license for the account mentioned above.

Hope there is someone can help me to answer the question above. 

Thanks 

Thanks and best regards.