I get 404 and i try everything

hi, i run keycloak on my local machine, and i use it as idp for my app that’s writing in asp.net. the first step I make the login success and the second step is to fetch the access token and this is the point I get 404
this is the URL to fetch the token http://localhost:8080/auth/realms/my-realm/protocol/openid-connect/token, I check all the parameters that I need to pass and everything looks good
grant_type=authorization_code&redirect_uri=" + baseUrl + “&code=” + code + “&client_id=” _authSettingInfo.LoginSetting.clientId + “&client_secret=” + _authSettingInfo.LoginSetting.clientSecret;

any idea what I miss ?