You will find the corresponding option inside
Dashboard >> Appearance >> customize >> General >> Custom Codes
Here, you will find the following options:
Tracking Code: You can enter your tracking codes here. This code will be enqueued in the site header. For example Google Tracking Code, Facebook Pixel Code, etc.
Custom JS: Header: Just want to do some quick JS changes? Enter them here, they will be applied to your theme.
Custom JS: Footer: Just want to do some quick JS changes? Enter them here, they will be applied to your theme.
