How to add a new realm-level scopeMapping

Using the admin API, how can I add a scopeMapping to the realm? This field can be seen when exporting the realm JSON, and in the UI it is under Client scopes>><client name>>>Scopes.

I am in the documentation, but there doesn’t seem to be any endpoint listed to perform requests on the realm-level “scopeMappings” field. It feels like there should be a path to /admin/realms/{realm}/scope-mappings, but there’s nothing. In case this field gets automatically populated in another request, please let me know which is the relevant request.

I can see there is a {realm}/client-scopes/{id}/scope-mappings, but this does not appear to be what I’m after, as the object structure is different. This object structure corresponds to the realm role.