Google notified developers back in 2018 that the company would stop supporting HTTP and JSON-RPC requests for its APIs. On the Google Webmaster Twitter handle, the announcement was made that this will be happening soon.
According to google, it continues “to see requests for the Search Console API like that.” This means that you may be using these methods.
Users are recommended to “check your implementations” to make sure that you aren’t using HTTP and JSON-RPC requests.