Hello. This is Klaytn API Service team.
Please refer to the following information about an error of an API call.
If the following error occurs even though the x-chain-id is correctly entered, please check if the request has a correct Authorization header first.
KAS uses the Basic HTTP Auth. Thus all requests must have a correct authorization header.
To do so, please access the KAS Console website and click on Credential under Security on the left-hand menu.
Then click on create AccessKey to download and safely store the file.
Please refer to the below method regarding the setup of an Authorization header.
1) First, select basic auth under the Authorization tab then enter the access key ID as the username and secret access key as the password.
2) Or you can also enter the ‘Authorization’ key directly onto the header.
Please try your API call again after entering the correct Authorization header as illustrated above.
Klaytn API Service team.