There are two kinds of collection you give your clients, and you make them in the same way.
A recipe book. Recipes bundled by theme, such as High protein or Quick weekday meals, with sections your client browses in the app. Found under Recipe books.
A collection. Links to outside sources: a playlist for training, the supplements you recommend, your online shop. Found under Collections. Fetch images gets a picture for links that didn’t have one yet; names you chose yourself stay as they are.
Making one. Give it a name and a short text, and add sections straight away; those are the chapters. Then you fill it in the window that opens.
For whom. Everyone at your business, or a few clients. Each collection shows how many clients it applies to.
Draft and publishing. A new collection starts as a draft: your clients can’t see it yet. Once it’s filled, you publish it. Withdraw from the app removes it from your clients again.