If you have recommender enabled for a size chart, by default the app would also inject a "what's my size" link which will open the recommender tab directly. The link also changes content depending on when a recommendation is made. As you can see in the following screenshot, there are 3 states of the button.

If you wish to remove this, you can do the following in settings. Go to settings, then click on "Recommender" tab.

Then in sizing injection selector, you can select the injection to be "Do not inject".