Problem with introspect

Hello! Please help me understand what I’m doing wrong. I get the access_token in the following way:

curl --request POST 
--header 'content-type: application/json'
--data '{"client_id":"$client_id","client_secret":"$client_secret", "audience":"API new","grant_type":"client_credentials"}'

Next, I want to check the validity of the access_token:

curl --request POST 
--url -H "Content-type:application/x-www-form-urlencoded" -d "client_id=$client_id&token_type_hint=access_token&token=$access_token"

I get “Not found” as a result
Please help in solving this problem. Thank you

As of right now, the CIC (fka Auth0) team provides assistance in a separate community forum. For example, I found this thread that discusses this: Missing Token introspection endpoint in openid configuration - #3 by dan.woda - Auth0 Community