Custom head tagsCustom meta tags and external CSS file tags can be added to your site in the Site settings > Template > Advanced tab > Custom head tags section.
Remote CSS link tags
An external CSS file may be included, for example, to use a remotely hosted font. The tag should look something like so:
<link rel="stylesheet" type="text/css" href="https://example.com/file.css">
Custom meta tags
These can be any kind of meta tag you wish. For example, if you sign-up for Google G Suite, you may need to use a special meta tag to verify you own the domain.
NOTE: You don't need to add meta tags hear for search optimization. These can be set elsewhere.