Set the package a client is signed up for — at creation or any time after.
A client's package determines which appointment types and add-ons are available to them. You can set it two ways.
When you create the client
On Step 2 of the New Client wizard, pick the package (and any add-ons) before finishing.
To change it later
Changing the package swaps the client's active package and updates their available appointment types automatically.
Tip: the packages themselves — names, prices, and which appointment types they include — are managed on the Packages page.