How to Create a New Service to Add to an Existing Membership
To create a new service to add to an existing membership, you will first need to create the new service.
In your Settings menu, click on Services, then click the Add New button to create a new service:

Add a Name for the new service. Since it will be free, leave the Price set at 0, and set the Length of the service:

Set Payment Options to Pay at Location Only. This means the customer will book without paying:

Near the bottom of this page is where you will set Booking Limits. Set this to Yes and set the Max Appointments restriction to 1 appointment per month. This membership has recurring billing so use the Per Month Rolling option and click Save.

Next, you will need to add Availability and Membership restriction to this service. Select the membership this service will be added to and click Add Requirement:

This new service is members only and it allows membership members to book 1 free golf lesson per month.

To review the membership you have added the new service to, go the the membership edit page and it will reveal that you have recurring monthly billing and a linked series for four free hours of sim time:

The new service that was created and assigned to the membership will appear here:

This membership now allows members to book 4 free hours of sim time per month using the linked series and 1 free golf lesson per month using the new service that was created with a max outstanding limit of 1 free lesson per month.